Printer Friendly

Foam Rolling and Joint Distraction with Elastic Band Training Performed for 5-7 Weeks Respectively Improve Lower Limb Flexibility.

Introduction

Developing flexibility by improving both active and passive range of motion (ROM) is crucial in many sporting activities. Static, ballistic and dynamic stretching as well as proprioceptive neuromuscular facilitation are relevant methods to increase ROM (Behm and Chaouachi, 2011; Behm et al., 2016; Kay and Blazevich, 2012; Page, 2012). Static stretching is one of the most widely used method, due to its simplicity and low risks of tissue trauma (Alter, 1988; Roberts and Wilson, 1999; Sady et al., 1982). Alternative techniques have been recently investigated. Among them, foam rolling (FR) through foam roller or roller massager became a very popular method to improve functional mobility and ROM (for an extensive review, see Cheatham et al., 2015). Likewise, variable resistance training using elastic bands may contribute to assist stretching techniques and improve flexibility by facilitating joint distraction and decoaptation, hence allowing the joint surfaces to gap away from one another (Page and Ellenbecker, 2003; Rosengart, 2013).

FR is believed to positively affect fibrous adhesions in the fascia, and to restore muscles, tendons, ligaments, fascia, and soft-tissue extensibility. Although he did not directly study the effect of FR, Barnes (1977) provided a theoretical framework for the possibility of affecting fibrous adhesions, while Schleip (2003) reported that supra-physiological forces are needed to break-up fascial adhesions. Cheatham et al. (2015) extensively described the impact of FR on the properties of the fascia (e.g., alteration of the viscoelastic and thixotropic properties), and how it contributed to increase the intramuscular temperature and blood flow. FR also results in reduced arterial stiffness and improved vascular endothelial function (Okamoto et al. 2014). The vast majority of experimental research revealed that FR may offer different kinds of benefits in terms of motor performance, flexibility and recovery (for reviews, see (Beardsley and Skarabot, 2015; Cheatham et al., 2015; Schroeder and Best, 2015; Kalichman and Ben David, 2017; Mauntel and Padua, 2014). Two studies even demonstrated that rolling the contralateral limb contributed to significant decreases in pain in the affected limb (Aboodarda et al., 2015; Cavanaugh et al., 2016). More generally, prophylactic effects of FR have been reported, due to its effect on the connective tissue and local blood flow. FR was found to attenuate the decrease in muscle performance, and both reduce and delay muscle soreness (Aboodarda et al., 2015; Cheatham et al., 2015; Jay et al. 2014; MacDonald et al., 2014; Pearcey et al., 2015; Schroeder and Best, 2015; Romero-Moraleda et al., 2017). Experimental studies did not report, in contrast, clear effects of FR when performed prior to motor performance. While it may not be harmful for subsequent performance, FR was not found to positively impact performance gains such as strength, power, jump, or shuttle run tasks (Fama and Bueti, 2011; Halperin et al., 2014; Healey et al., 2014; Jones et al. 2015; Mikesky et al., 2002; Peacock et al. 2015, but see the recent study by Romero-Moraleda et al., 2017 for positive effects of FR on strength). Interestingly, and despite some conflicting results (Couture et al., 2015), FR has been found to substantially increase ROM of the hip (Behara and Jacobson, 2015; Bushell et al., 2015; De Souza et al., 2017; Mohr et al., 2014; Monteiro et al. 2017), knee (Button and Behm, 2014; Bradbury-Squires et al., 2015; MacDonald et al., 2013, 2014; MacDonald et al., 2013; 2014; Vigotsky et al., 2015), and ankle (De Souza et al., 2017; Halperin et al., 2014; Skarabot et al., 2015), without hampering muscle performance (see Halperin et al., 2014). Similar findings were reported for the sit and reach test (Sullivan et al., 2013; Pearcey et al., 2015). As both FR and stretching are likely to improve ROM, combining these two types of practice may result in greater performance gains (MacDonald et al., 2014; Roylance et al., 2013; Skarabot et al., 2015). Altogether, these data support the benefits of FR for enhancing joint ROM (Cheatham et al., 2015). While some studies compared the effectiveness of different types of roller (during either pre or post-exercise), as well as the nature and the duration of the massage pressure (Cheatham et al., 2015; Curran et al. 2008; Debruyne et al., 2017; De Souza et al., 2017; Monteiro et al., 2017), the effects of a longer FR intervention targeting several muscles on ROM, throughout several training sessions, has received little attention. Junker and Stoggl (2015) investigated the effectiveness of a 4-week training with the foam roll method on hamstring flexibility. They provided evidence that FR is effective to improve range of motion, such beneficial effects being comparable with those provided by the well-known contract-relax proprioceptive neuromuscular facilitation stretching method. There is a lack of unanimity in the literature, however, as a recent study by Hodgson et al. (2018) did not show improved flexibility after 4 weeks of rolling. Spurred by the positive findings and due to the conflict in the scientific literature, further experimental data looking at the long-term effects of FR are required to confirm the benefits of FR on the thixotropic properties of the muscle (Axelson and Hagbarth, 2001), with long-term effects which may arise from decreasing tissue adhesion (McHugh et al., 2012), and improving fascia elasticity (Wilke et al., 2016).

Joint distraction with elastic bands training (EBT) is another emerging and cost-effective component of strength and conditioning programs. Traditionally, this method has been used for strengthening muscle and improving power and velocity (Jakobsen et al., 2013; Joy et al., 2016; Jakubiak and Saunders, 2008; Rhea et al., 2009; Smith et al., 2011; Treiber et al., 1998). As well, EBT has been found to enhance jumping and sprinting performance, hence providing an alternative training method as a part of plyometric programs (Argus et al., 2011; Janot et al., 2013) or during warm-up (Wyland et al., 2015). Soria-Gila et al. (2015) reported that EBT might even result in greater strength gains than conventional weight training, while Park et al. (2015) illustrated its benefits to improve endurance, balance, agility and quality of life in elderly persons (see also Oesen et al., 2015, but Vinstrup et al., 2016, for challenging results). Another promising effect of EBT is that it may facilitate the effectiveness of motor recovery by maximizing strength gains in injured athletes while being less boring than conventional stretching, and therefore more likely to be adhered to (Lorentz, 2014). Surprisingly, very few studies investigated the effect of EBT on flexibility, although its properties make it ideal for providing load during stretching exercises (Carrio, 2012; Donatelli and McMahon, 1997; Page and Ellenbecker, 2003). Practically, joint distraction exercises might be incorporated during stretching routines in order to create more space in the joint complex (Rosengart, 2013). During joint distraction, elastic bands act as wedges to separate the joint surfaces from one another (Rosengart, 2013), hence presumably providing more space for synovial fluid to fill the joint and reduce the amount of friction (Bourneton, 1981; Le Roux and Dupas, 1995). Another advantage is that the resistance can be individually adjusted to the tolerance of the person. Joint distraction using elastic bands might thus be used not only to assist static stretching, but also active and dynamic stretching. Including elastic band training in a specific experimental protocol designed to improve flexibility appeared an original approach which has been quite neglected in the literature, with the advantage of providing an individualized form of practice with a constant traction. In addition, due to its self-adjusting nature, elastic band exercises allow participants to apply a closed-loop motor control to promote and reinforce joint distraction before performing the stretching routine.

The present study included two experiments designed to respectively investigate the effectiveness of FR and EBT on range of motion in national rugby players. In contrast to the majority of experimental studies looking at the immediate and short term effects on functional performance, we tested the effect of a 7-week training program on the performance of several stretching exercises. We hypothesized that both FR and EBT would contribute to improve joint flexibility and facilitate stretching processes.

Methods

Participants

Thirty professional national-level male rugby players (M = 18.85 years, SD = 1.10 years) voluntarily participated in Experiment 1. Twenty-three professional national-level male rugby players (M = 17.22 years, SD = 0.60 years) were recruited for Experiment 2, which was performed 1 month after Experiment 1. None of the participants were enrolled in both experiments, so that all players were selected from different Rugby teams. Anthropometric characteristics of the participants are displayed in Table 1. Players provided written and informed consent in agreement with the terms of the Declaration of Helsinki (1982). Prior ethical approval was granted by the Research Ethics Committee of the Center of Research and Innovation in Sport (University Claude Bernard Lyon 1). Any foam rolling training was suspended for 72 h prior to each experiment, and participants were requested to not practice outside of the supervised sessions until completion of the experimental procedure. Participants were not enrolled if they had suffered from any traumatic injury requiring a healing rest-period during the month preceding the experiments. None of the participants was injured during the experimental interventions.

Experimental designs

Experiment 1

The test-retest study spanned over a 7-week period and consisted in a pre-test (Week 0), a FR intervention including 15 rolling sessions (Weeks 1-6), and a post-test (Week 7, Figure 1). Participants were randomly assigned to one of three groups (n = 10 in each group) that differed in the activities to be performed during the FR intervention (Figure 1). Two experimental groups were subjected to supervised FR sessions. The [FR.sub.40] group foam rolled each target muscle during 40s, while the [FR.sub.20] group foam rolled muscles during 20s, and then had rest for the remaining time. A third Control group did not perform any kind of FR, but only a neutral activity during an equivalent amount of time (i.e., active constant low-intensity cycling task, at 50% of the VO2, controlling the engagement in a self-regulated form of practice involving the lower limbs). All groups therefore spent similar total time in the presence of the experimenter. To ensure participants' blindness, participants from the Control group were planned to benefit from each experimental procedure later in the season, while the experimental groups would be subjected to the active constant low-intensity cycling task during equivalent time.

Pre- and post-test sessions included different ROM measures performed by a physical therapist blinded to which intervention the participant was randomized to. Data were collected with an electronic goniometer (MLTS700, AD Instruments, Sydney, NSW, Australia) after a brief standardized and controlled warm-up (3 min home trainer cycling at moderate intensity, 10 squats and lunges without resistance, 3 countermovement jumps and 3 squat jumps, 10 sprints of 10 m), during the following exercises, which were administered in a randomized order: side split, hip flexion (both active straight leg raising and active flexed leg raising), hip extension, knee flexion, and ankle dorsiflexion. Although rugby performance does not require a high level of flexibility, improving joint flexibility during standardized split exercises or sit and reach test seems relevant to adopt a prophylactic approach. All participants were scheduled at the same time for testing, unilateral measures being subsequently collected in both sides (except for the side split). For the side split, participants laid on their back with legs straight up the wall, and let legs draw apart up to the maximal amplitude, with feet sliding down the wall. The axis of the goniometer was placed on the midline of the pelvis, the stationary and moving arms being aligned with the internal condyles. Hip flexion was measured from the supine position. For the active straight leg raising, participants performed a straight leg raise up to the maximal amplitude, and then maintained the final position (Goeken and Hof, 1991; Cho et al., 2015). The axis of the goniometer was on the grand trochanter, the stationary arm was aligned with the lateral malleolus of the opposite leg, and the moving arm was aligned with the lateral epicondyle of the femur (usual men reference values based on the position of the goniometer = 90[degrees]). For the active flexed leg raising, the hip, with the knee flexed, was progressively flexed up to the chest (Harvey, 1998; Su et al., 2017). The axis of the goniometer was on the lateral epicondyle of the femur, the stationary arm was aligned with the grand trochanter and the moving arm was aligned with the lateral malleolus (usual men reference values based on the position of the goniometer = 0[degrees] to 130[degrees]). These two measures of hip flexion were selected as they were likely to provide complementary information about hip mobility by targeting different muscles and, therefore, both passive and dynamic hip flexibility. Hip extension and knee flexion were collected from the modified Thomas test position, participants lying supine at the edge of an examination table and holding the uninvolved knee flexed to the chest. This test is frequently used by rugby practitioners. For the hip extension, particular attention was paid to control the pelvic tilt (Vigotsky et al., 2016). The axis of the goniometer was placed on the grand trochanter, the stationary arm was aligned with the midline of the pelvis and the moving arm with the lateral epicondyle of the femur (usual men reference values based on the position of the goniometer = 180[degrees] to 170[degrees]). For measuring the knee flexion, the axis of the goniometer was on the lateral epicondyle of the femur, the stationary arm was aligned with the grand trochanter and the moving arm was aligned with the lateral malleolus. Finally, active ankle dorsiflexion was measured from the weight-bearing lunge test position (Bennell et al., 1998; Kelly and Beardsley, 2016). Participants stood with their foot approximately 10 cm back, perpendicular to the wall. They were then instructed to look forward and to flex their knee until it reached the wall. The knee was to touch the wall, travel over the mid-line of the foot and the heel was to stay firmly on the ground. Participants were asked to slide their foot forward or back depending whether their knee failed or successfully touched the wall, and prevent any elevation of the heel. The axis of the goniometer was placed on the lateral malleolus, the stationary arm was aligned with the fibular head and the moving arm was aligned with the fifth metatarsal. In each case, the mean of three consecutive measures performed by the same experimenter was considered (usual men reference values based on the position of the goniometer = 90[degrees] to 50[degrees]).

The FR intervention was self-administered by the participants under the direct supervision of the same experimenter, throughout the experimental design. A similar 91 cm high-density (51 kg.[m.sup.3]) foam roller was used by each athlete. Five muscles were successively foam-rolled on both right and left sides, separately (hip extensors, hip adductors, knee extensors, knee flexors and plantar flexors). The protocol consisted of one bout for each muscle, participants rolling back and forth between insertions. For each muscle, participants from the [FR.sub.20] and [FR.sub.40] respectively performed 7 and 14 back and forth movements (i.e. each back and forth movement did not exceed 3s). FR procedures are summarized in Figure 1. For the hip extensor, participants sat on the floor and placed the foam roller on the top of the muscle, the other leg and the hands supporting the body during the back and forth movement. To roll out the hip adductor, participants lied face down to the ground, resting on the forearms, and placed the roller under the side of the knee flexed out of a side at 90[degrees]. They then moved back and forth the roller up to the inner thigh. For the knee extensor, participants also lied face down on the floor resting on the forearms, with the foam roller at the top of their quadriceps, and foam rolled from the top to the bottom, above the patella. To foam roll the knee flexor, participants rolled from the ischial tuberosity to the back of the knee. Hands were set on the floor without moving, and participants shifted their body back and forth, guiding the movement with the contralateral leg. Finally, for the plantar flexor, participants sat on the floor with the foam roller placed below the knee joint, and rolled back and forth to the ankle joint.

Overall, participants were requested to support their body weight with the arms and the other leg during the FR protocol. While the pressure applied on the tissue was not directly controlled, participants were asked to carefully apply pressure on the targeted muscle group during FR. Pain and comfort were managed by the participants during each exercise. Subjective reports delivered by the participants did not reveal discomfort o the target muscle or other place. In particular, they did not feel that the arms were overloaded while supporting the body weight during the exercises.

Experiment 2

The test-retest study spanned over a 5-week period and consisted of a pre-test (Week 0), a variable resistance training including 24 sessions of elastic band exercises (Weeks 1-4), and a post-test (Week 5). Participants were randomly assigned to an experimental (n = 13) or a Control group (n = 10) that differed in the activities to be performed during the intervention. The experimental group used elastic band resistance to assist four active exercises for the mobility of the hip (24 sessions). EBT was self-administered by the participants under the direct supervision of the experimenter, throughout the experimental design. EBT exercises were performed on each side for 35 s (Figure 2). The traction exerted by the elastic band (tension of 18 [+ or -] 2 Kg) should remain in a predetermined comfort range, without eliciting pain. Participants were orally asked about their comfort as soon as they reached the targeted position for each exercise. For the first exercise, participants lunged forwards with the front leg at a right angle, and the back knee to foot along the ground. Elastic resistance was applied on the back leg, below the gluteus maximus, in order to tract the femoral head backward. The second exercise started from the same lunge position, but the elastic resistance was applied on the back leg, below the gluteus maximus, in order to tract the femoral head forward. In the third exercise, participants lied on their back on the floor and extended the leg out straight with the toes pointing up. The elastic resistance was applied in order to tract the femoral head backward. Finally, for the last exercise, participants flexed their front leg at 90[degrees] and straightened their back leg behind. The elastic resistance was again applied below the gluteus maximus in order to tract the femoral head backward. Before the beginning of the experimental procedure, the experimenter checked that all participants were able to spend less than 40s to appropriately place the elastic bands, using a video tutorial, and, if needed, instructor assistance. The experimenter subjectively reported a low inter-individual variability in terms of preparation time for the exercises. The Control group performed a neutral activity, i.e. adopting a passive postural training of the lower limbs without any elastic band resistance, during an equivalent amount of time. Each group therefore spent similar total time to practice in the presence of the experimenter. As in Experiment 1, participants' blindness was controlled as the experimental procedure was integrated into a large training protocol including several periods of specific practice. Specifically, players from the control group were likely to benefit from the experimental procedure later in the season, while participants from the experimental group would be subjected to the passive postural training during equivalent time.

Pre- and post-test sessions included different ROM measures performed by a physical therapist blinded as to group allocation. Data were collected after the same standardized and controlled warm-up than Experiment 1, during the following exercises: side split from a seated position, side split lying on the back against a wall, front split and the sit-and-reach test. All testing measures were scheduled at the same time of the day to avoid circadian influences. For the seated side split, participants sat on the floor, opened their straight lean, and stretched their body forward between their legs, up to the maximal amplitude with a straight back. The side split against a wall was performed while lying on the back, with feet sliding down the wall. Flexibility score for the two side split exercises was evaluated through the distance between the two internal malleolus, legs being separated to the maximum. For the front split, participants stood on the floor while extending the front leg forward and keeping the back straight. Range of motion was determined by the distance between the ischial tuberosity of the front leg and the floor. Finally, the flexibility of hamstrings muscles was evaluated with the sit and reach test. Participants seated on the floor and reached towards the toes as far as possible. Flexibility score was recorded to the nearest centimeter from the distance above (negative) or past (positive) the toes.

Statistical analysis

We used R (R Core team, 2015) to perform a parametric analysis of the dependent variables of interest (i.e., ROM of the target muscles for Experiment 1, metric measures of stretch performance for the seated, side and front splits, as well as for the sit-and-reach test for Experiment 2). Visual inspection of Q-Q plots did not reveal any obvious deviations from normality for both experiments. In Experiment 1, we used a two-way analysis of variance with repeated measures testing the effect of Group ([FR.sub.40], [FR.sub.20] and Control) and Test (Pretest, Posttest) on ROM measures. In Experiment 2, we carried on a two-way analysis of variance with repeated measures to test the effect of Group (EBT, Control) and Test (Pretest, Posttest) on the stretching performance. The statistical significance threshold was settled for a type 1 error rate of 5%. As measure of effect size, we calculated and reported the partial eta-squared. As post-hoc investigations, we used Student's t-tests for paired and independent samples and applied Holm's sequential corrections to control the false discovery rate (Holm, 1979).

Results

Experiment 1

Data revealed a significant Group x Test interaction for the side split ([F.sub.(2, 54)] = 3.56, [[eta].sup.2]p = 0.13, p = 0.03), the active flexion of the right and left hips ([F.sub.(2, 54)] = 4.59, [[eta].sup.2]p = 0.17, p = 0.01, and [F.sub.(2, 54)] = 3.23, [[eta].sup.2]p = 0.12, p = 0.04, respectively), the passive flexion of the right and left hips ([F.sub.(2, 54]) = 5.31, [[eta].sup.2]p = 0.20, p = 0.007, and [F.sub.(2, 54)] = 3.60, [[eta].sup.2]p = 0.13, p = 0.03, respectively), as well as the extension of the right and left hips ([F.sub.(2, 54)] = 10.63, [[eta].sup.2]p = 0.39, p < 0.001, and Fa 54)=9.68, [[eta].sup.2]p = 0.36, p < 0.001). No interaction was found for the flexion of the right and left knees (F(2, 54) = 0.63, [[eta].sup.2]p = 0.02, p = 0.53, and ([F.sub.(2, 54)] = 0.77, [[eta].sup.2]p = 0.02, p = 0.46), and the active dorsiflexion of both right and left ankles (([F.sub.(2, 54)] = 0.41, [[eta].sup.2]p = 0.01, p = 0.66, and ([F.sub.(2, 54)] = 0.56, [[eta].sup.2]p = 0.02, p = 0.57).

Post-hoc tests yielded no statistically significant difference during the pre-test between [FR.sub.40] and [FR.sub.20] and Control groups for all dependent variables of interest (all p > 0.05, Figure 4). Interestingly, both [FR.sub.40] and [FR.sub.20] groups improved their performance from the pre- to the post-test, and significantly outperformed the Control group for the side split, hip flexion (active straight and flexed leg raising), and the hip extension (Figures 3 and 4, Tables 2 and 3). For the side split, performance improved by 17.70[degrees] in the [FR.sub.20] group (t = 3.6, [CL.sub.95%] = [-28.04 / -7.36], p = 0.002; i.e., +16.25% relative to the pretest values) and 18.00[degrees] (i.e., +16.53%) in the [FR.sub.40] group (t = 3.22, [CL.sub.95%] = [-29.82 / -6.18], p = 0.005), while ROM did not change in the CTRL group (+1.80[degrees], t = 0.43, [CL.sub.95%] = [-10.54 / 6.94], p = 0.67). For the right and left active straight leg raising, the [FR.sub.20] group respectively improved performance by 14.00[degrees] (t = 3.35, [CL.sub.95%] = [-22.89 / -5.11], +18.56%, p = 0.004) and 9.20[degrees] (t = 1.95, [CL.sub.95%] = [19.10 / -0.70], +12.16%, p = 0.06).

As well, the [FR.sub.40] group improved performance by 6.20[degrees] for the right side (t=3.57, [CL.sub.95%] = [-25.77 / -6.63], +8.21% p=0.002) and 15.70[degrees] for the left side (t = 3.42, [CL.sub.95%] = [-25.34 / -6.06], +20.58%, p = 0.003), whereas no change in performance was observed for the Control group (+0.60[degrees] for the right side and +0.10[degrees] for the left side, t = 0.21, [CL.sub.95%] = [-6.75 / 5.55], p = 0.84, and t = 0.03, [CL.sub.95%] = [-7.92 / 7.72], p = 0.98, respectively). For the active flexed leg raising, the [FR.sub.20] group respectively improved performance by 14.20[degrees] for the right side (t = 3.51, [CL.sub.95%] = [-22.93 / -5.47], +16.55%, p = 0.004) and 11.50[degrees] for the left side (t = 2.79, [CL.sub.95%] = [-20.20 / -2.80], +12.93%, p = 0.01). As well, the [FR.sub.40] group improved performance by 16.90[degrees] cm for the right side (t = 4.35, [CL.sub.95%] = [-25.22 / -8.58], +19.69%, p < 0.001) and 16.40[degrees] for the left side (t = 4.09, [CL.sub.95%] = [-24.83 / -7.97], +18.94%, p < 0.001), while no difference was found when comparing data from the Control group (1.80[degrees] for the right side and -0.10[degrees] for the left side, t = 0.35, [CL.sub.95%] = [-8.96 / 12.56], p = 0.73, and t = 0.02, [CL.sub.95%] = [-10.78 / 10.98], p = 0.98, respectively). For the hip extension, the [FR.sub.20] group respectively improved performance by 17.10[degrees] for the right side (t = 7.15, [CL.sub.95%] = [-22.12 / -12.08], +9.81%, p < 0.001) and 15.50[degrees] for the left side (t = 6.67, [CL.sub.95%] = [-20.38 / -10.62], +8.82%, p < 0.001). Likewise, the [FR.sub.40] group improved performance by 15.10[degrees] cm for the right side (t = 5.40, [CL.sub.95%] = [-21.00 / -9.20], +8.66%, p < 0.001) and 13.50[degrees] for the left side (t = 5.90, [CL.sub.95%] = [-18.31 / -8.69], +7.79%, p < 0.001), while the Control group did not show any change in performance (+0.90[degrees] for the right side and +0.70[degrees] for the left side, t = 0.31, [CL.sub.95%] = [-7.03 / 5.23], p = 0.76, and t = 0.23, [CL.sub.95%] = [-7.19 / 5.79], p = 0.82, respectively). Finally, no group difference was found when comparing changes in performance from the [FR.sub.20] and [FR.sub.40] groups for any ROM measure (p > 0.05).

Finally, participants subjectively reported that they experienced greater discomfort when foam-rolling target muscles during 40s compared to 20s.

Experiment 2

Data revealed a significant Group x Test interaction for the front split ([F.sub.(1, 21)] = 21.21, [[eta].sup.2]p = 1.00, p < 0.001) and sit and reach test ([F.sub.(1, 21)] = 7.34, [[eta].sup.2]p = 0.35, p = 0.01). No interaction was found for the seated side split and the side split against the wall ([F.sub.(1, 21)] = 0.23, [[eta].sup.2]p = 0.01, p = 0.64, and [F.sub.(1, 21)] = 0.04, [[eta].sup.2]p = 0.001, p = 0.84, respectively). No main Group or Test effect was observed for these two measures.

Post-hoc tests revealed no statistically significant difference during the pre-test between the Control and EBT groups for all stretching variables (all p > 0.05, Figure 5). The post-hoc analysis yielded that the EBT group improved performance from the pre- to the post-test, while there was no substantial change in performance for the Control group (Figure 5, Table 4). For the front split, performance was improved by 3.38 cm (i.e., +2.31% relative to the pretest) in the EBT group (t = 5.14, [CL.sub.95%] = [-4.8 / -1.95], p < 0.001), while ROM did not change in the Control group (-0.45 cm, t = 1.11, [CL.sub.95%] = [-0.47 / 1.36], p = 0.29). For the sit and reach test, the EBT group significantly improved performance by 1.35 cm (t = 2.96, [CL.sub.95%] = [-2.34 / -0.36], +29.16%, p = 0.01), while ROM did not change in the Control group (-0.15 cm t = 0.7, [CL.sub.95%] = [-0.32 / 0.63], p = 0.50).

Discussion

The present study was designed to evaluate whether a training program of several FR or EBT sessions might enhance flexibility in expert rugby players. Overall, results demonstrated the effectiveness of these two forms of practice and therefore support their relevance as an adjunctive training method to enhance flexibility.

In contrast to previous studies which primarily investigated the short-term effects of FR on flexibility (i.e., test-retest following one single session), we tested the effects of a 7-week training program. Data provided evidence of significant increases in ROM during side split performance, as well as hip extension and both passive and active hip flexion, bilaterally. This finding corroborates the results pattern yielded by previous short-term interventions, which underlined the positive effects of FR on hip ROM (Behara and Jacobson, 2015; Bushell et al., 2015; Cheatham et al., 2015; De Souza et al., 2017). While challenging the recent study by Hodgson et al. (2018), these findings are in keeping with the study by Junker and Stoggl (2015), who explored the effects of a 4-week period of FR on hamstring flexibility. Mohr et al. (2014) reported that FR followed by static stretching contributed to increase the intramuscular tissue temperature and blood flow, and concomitantly reduce viscosity due to changes in the thixotropic properties of the muscle. Such FR-induced changes in the histological properties may explain, at least partially, the observed ROM improvements. Unexpectedly, the lack of positive effects of FR for the ankle dorsiflexion and the knee flexion are in disagreement with previous experimental data (Button and Behm, 2014; Bradbury-Squires et al., 2015; Halperin et al., 2014; MacDonald et al., 2013; 2014; Vigotsly et al. 2015; Skarabot et al., 2015; De Souza et al., 2017). While the use of a stick might be more efficient to investigate the effects of FR on ankle ROM (Halperin et al., 2014), such important difference in the results pattern may be explained by the fact that, in the present study, both the quadriceps and the triceps surae muscles were not in a stretched position when athletes performed FR. This possibly limited performance gains. This assumption is congruent with the fact that under the other experimental conditions, where FR was practiced on stretched muscles, positive effects were recorded. Furthermore, the half kneeling dorsiflexion involves mainly the soleus muscle while gastrocnemii muscles are slack (Cresswell et al., 1995; Maisetti et al., 2012). Considering that the FR protocol was applied on the gastrocnemii, it might likely explain the absence of increase in dorsiflexion ROM.

Practically, including FR as a part of training programs designed to develop stretching capacities constitutes a promising avenue for both practitioners and clinicians. As suggested by Mohr et al. (2014) and Skarabot et al. (2015), combining FR and static stretching might be the optimal strategy to increase ROM and improve stretching performance. Interestingly, our data did not show any difference when comparing performance from the [FR.sub.20] and the [FR.sub.40] groups. This finding corroborates previous research by De Souza et al. (2017), who provided evidence that increasing the FR volume from 10 to 20 repetitions per set did not promote additional gains. In the present study, participants however experienced greater discomfort when foam-rolling target muscles during 40 sec. In terms of practical applications, these findings thus suggest that FR each muscle during 20s is sufficient and might be regularly included as part of a stretching routine.

Joint distraction techniques are commonly used to alleviate pain and are casually administered to patients in clinical settings (Cahill and Theopold, 2016). Their use to enhance performance in athlete is quite novel. Elastic bands provide a constant resistance expected to maximize its mechanical effects, i.e., increase in synovial fluid motion bringing nutrients to the avascular portions of the intra-articular fibro-cartilage (Kisner and Cloby, 2012). Based on present data in rugby players, we hypothesized that this would not only result in lower pain, but may also contribute to improve flexibility and ROM. Interestingly, results of Experiment 2 showed that compared to a passive postural training, performing joint distraction using elastic band resistance during 5 weeks resulted in stretching gains during both the front split and the sit and reach test. Yet, scientific reports of such effects of EBT remain sparse in the scientific literature, albeit some authors underlined its empirical efficacy (Carrio, 2012; Rosengart, 2013).

Specifically, significant performance gains were observed for stretching movements primarily involving the hamstrings, which are strongly involved during active running phases in rugby, but also commonly injured (Roberts et al., 2013). Stretching routines combined with joint distraction and EBT may specifically improve ROM of muscles which are highly stressed during actual practice. Accordingly, selective effects on muscles predominantly involved in rugby-specific tasks should be expected. This is congruent with the fact that adductors flexibility (a determinant of side split performance) is secondary compared to that of the hamstrings in most rugby actions. Finally, recent results showed that both dynamic and static stretching had no influence on hamstrings response times, and therefore did not contribute to reduce this primary risk factor for anterior cruciate ligament injury (Ayala et al., 2013; 2014). Replicating a similar set of measures after a program of active/dynamic stretching assisted by joint distraction with elastic band resistance might be of interest to investigate injury prevention more extensively.

The fact that EBT facilitated stretching performance for hamstrings exercises but did not substantially impact the flexibility of the adductors might also be explained by the nature of the traction applied during the joint distraction tasks. Accordingly, the elastic band was systematically wrapped to the pelvis along the antero-posterior axis, thus possibly limiting the effects on the mobility of the adductors, while facilitating more extensively the flexibility of the hamstrings. Although less frequently performed in EBT routines, wrapping the elastic band around the thigh, up close towards the knee, while keeping the body perpendicular to the band, might be more beneficial to target the flexibility of the adductors.

Aside the relatively small sample sizes tested in these two experiments, one main limitation of the present study is that ROM, collected using an electronic goniometer placed on the joint of interest, was the only one outcome. Even if care was taken to the joint of interest, the angle of other joints was therefore not directly considered. As shown recently by Andrade et al. (2016), who showed the influence of the hip position in the ankle ROM, one cannot totally rule out the influence of the other joints on the targeted ROM. Another limitation is that the Thomas test is certainly not the most appropriate way to assess knee mobility, as the knee flexion might increase not because of worse flexibility, but rather due to the position of the thigh during the test. This test, which remains frequently used by practitioners, is indicative, but should ideally be combined with another assessment. Otherwise, participants were not allocated to groups controlling their rugby field position, which may be interesting in future experimental studies. In addition, although we controlled in the two experiments that the main rugby training activity was performed by all players during the intervention period, future studies should ideally include participants who do not train rugby at all during the intervention.

Conclusion

Taken together, present findings suggest that a training program including either FR or joint distraction exercises with elastic bands is likely to enhance joint ROM as well as specific mobility patterns. The findings have thus strong implications in terms of prophylaxis in athletes such as rugby players but also in non-athletes. Data also revealed that FR substantially improved players' flexibility scores regardless the rolling duration, and that EBT primarily contributes to improve ROM for muscles highly stressed during actual practice. Along with previous results from the scientific literature, as well as empirical findings, the present study confirms that these two forms of practice constitute a promising avenue for clinical, home therapy, and personal flexibility training. Whether improvements in flexibility might positively influence subsequent motor and sport performance remain uncertain. Medeiros and Lima (2017) nicely reviewed the experimental studies investigating the influence of stretching on muscle performance. Interestingly, they reported that while some studies showed some improvements in muscle performance after flexibility training, the selective influence of this latter form of practice remains difficult to interpret and comprehend. Future experimental research will certainly contribute to resolve this issue.

Key points

* Foam rolling substantially improved hip range of motion scores, regardless the rolling duration.

* Joint distraction with elastic bands significantly improved sit-and-reach as well as side split stretching performances.

* Foam rolling and joint distraction exercises with elastic bands appear of specific interest to improve flexibility and serve prophylaxis.

Acknowledgements

The experiments comply with the current laws of the country in which they were performed. The authors have no conflicts of interests to declare.

References

Aboodarda, S.J., Spence, A.J. and Button, D.C. (2015) Pain pressure threshold of a muscle tender spot increases following local and non-local rolling massage. BMC Musculoskeletal Disorders 16, 265.

Alter, M.J. (1988) Science of stretching. Champaign, IL: Human Kinetic Books.

Andrade, R.J., Lacourpaille, L., Freitas, S.R., McNair, P.J. and Nordez, A. (2016) Effects of hip and head position on ankle range of motion, ankle passive torque, and passive gastrocnemius tension. Scandinavian Journal of Medicine and Science in Sports 26, 41-47.

Argus, C.K., Gill, N.D., Keogh, J.W., Blazevich, A.J. and Hopkins, W.G. (2011) Kinetic and training comparisons between assisted, resisted, and free countermovement jumps. Journal of Strength and Conditioning Research 25, 2219-2227.

Axelson, H.W. and Hagbarth, K.E. (2001) Human motor control consequences of thixotropic changes in muscular short-range stiffness. Journal of Physiology 535, 279-288.

Ayala, F., De Ste Croix, M., Sainz De Baranda, P. and Santonja, F. (2013) Acute effects of static and dynamic stretching on hamstring eccentric isokinetic strength and unilateral hamstring to quadriceps strength ratios. Journal of Sports Sciences 31, 831-839.

Ayala, F., De Ste Croix, M., Sainz De Baranda, P. and Santonja, F. (2014) Acute effects of static and dynamic stretching on hamstrings' response times. Journal of Sports Sciences 32, 817-825.

Barnes, J. (1977) The basic science of myofascial release. Journal of Bodywork and Movement Therapies 1, 231-238.

Beardsley, C. and Skarabot, J. (2015) Effects of self-myofascial release: A systematic review. Journal of Bodywork and Movement Therapies 19, 747-758.

Behara, B. and Jacobson, B.H. (2015) The acute effects of deep tissue foam rolling and dynamic stretching on muscular strength, power, and flexibility in division I linemen. Journal of Orthopedic Trauma 31, 888-892.

Behm, D. G., Blazevich, A. J., Kay, A. D. and McHugh, M. (2016) Systematic Review: Acute Effects of Muscle Stretching on Physical Performance, Range of Motion and Injury Incidence in Healthy Active Individuals. Applied Physiology Nutrition and Metabolism. Applied Physiology Nutrition and Metabolism 40, 1-11.

Behm, D. G. and Chaouachi, A. (2011) A review of the acute effects of static and dynamic stretching on performance. European Journal of Applied Physiology 111, 2633-2651.

Bennell, K., Talbot, R., and Wajswelner, H. (1998) Intra-rater and interrater reliability of a weight-bearing lunge measure of ankle dorsiflexion. Australian Journal of Physiotherapy 44, 175-180.

Bourneton, A. (1981) Utilisation des tractions electromecaniques intermittentes dans les pathologies de l'epaule et de la hanche. Annales de Kinesitherapie 8, 245-255 [article in French].

Bradbury-Squires, D.J., Noftall, J.C., Sullivan, K.M., Behm, D.G., Power, K.E. and Button, D.C. (2015). Roller-massager application to the quadriceps and knee-joint range of motion and neuromuscular efficiency during a lunge. Journal of Athletic Training 50, 133-140.

Bushell, J.E., Dawson, S.M. and Webster, M.M. (2015) Clinical Relevance of Foam Rolling on Hip Extension Angle in a Functional Lunge Position. Journal of Strength and Conditioning Research 29, 2397-2403.

Button, D.C. and Behm, D.G. (2014) Foam rolling: Early study findings suggest benefits. Lower Extremity Review Available from URL: http://lermagazine.com/article/foam-rolling-early-study-findings-suggest-benefits.

Cahill, K.C., Theopold, C. and O'Shaughnessy, M. (2016) Experiences with pins and rubber band traction in the treatment of proximal interphalangeal joint contracture. Plastic Surgery (Oakville) 24, 20-22.

Carrio, C. (2012) Un corps sans douleur [A body without pain]. Thierry Souccar Editions.

Cavanaugh, M.T., Doweling, A., Young, J.D., Quigley, P.J., Hodgson, D.D., Whitten, J.H.D., Reid, J.C., Aboodarda, S.J., and Behm, D.G. (2016) An acute session of roller massage prolongs voluntary torque development and diminishes evoked pain. European Journal of Applied Physiology 117, 109-117.

Cheatham, S.W., Kolber, M.J., Cain, M. and Lee, M. (2015) The effects of self-myofascial release using a foam roll or roller massager on joint range of motion, muscle recovery, and performance: A systematic review. International Journal of Sports and Physical Therapy 10, 827-838.

Cho S. H., Kim, S. H., and Park, D. J. (2015) The comparison of the immediate effects of application of the suboccipital muscle inhibition and self-myofascial release techniques in the suboccipital region on short hamstring. Journal of Physical Therapy Sciences 27, 195-197.

Couture, G., Karlik, D., Glass, S.C. and Hatzel, B.M. (2015) The effect of foam rolling duration on hamstring range of motion. Open Orthopaedics Journal 9, 450-455.

Cresswell, A.G., Loscher, W.N. and Thorstensson, A. (1995) Influence of gastrocnemius muscle length on triceps surae torque development and electromyographic activity in man. Experimental Brain Research 105, 283-390.

Curran, P.F., Fiore, R.D. and Crisco, J.J. (2008) A comparison of the pressure exerted on soft tissue by 2 myofascial rollers. Journal of Sport Rehabilitation 17, 432-442.

De Souza, A., Sanchotene, C.G., da Silva Lopes, C.M., Beck, J.A., da Silva, A.C.K., Pereira, S.M. and Ruschel, C. (2017) Acute Effect of Two Self-Myofascial Release Protocols on Hip and Ankle Range of Motion. Journal of Sport Rehabilitation 15, 1-21.

Debruyne, D.M., Dewhurst, M.M., Fischer, K.M., Wojtanowski, M.S. and Durall, C. (2017) Self-Mobilization Using a Foam Roller Versus a Roller Massager: Which Is More Effective for Increasing Hamstrings Flexibility? Journal of Sport Rehabilitation 26, 94-100.

Donatelli, R.A. and McMahon, T.J. (1997) Manual therapy techniques (Chap. 14). In Physical Therapy of the Shoulder. Ed: Donatelli R. 3rd edition. Churchill-Livingstone. 347-348.

Fama, B.J. and Bueti, D.R. (2011) The acute effect of self-myofascial release on lower extremity plyometric performance. [Dissertation Thesis], Sacred Heart University, USA.

Goeken, L. N., and Hof, A. L. (1991) Instrumental straight-leg raising: a new approach to Lasegue's test. Archives in Physical Medicine and Rehabilitation 72, 959-966.

Halperin, I., Aboodarda, S.J., Button, D.C., Andersen, L.L. and Behm, D.G. (2014) Roller massager improves range of motion of plantar flexor muscles without subsequent decreases in force parameters. International Journal of Sports and Physical Therapy 9, 92-102.

Harvey, D. (1998) Assessment of the flexibility of elite athletes using the modified Thomas test. British Journal of Sports Medicine 32(1), 68-70.

Healey, K.C., Hatfield, D.L., Blanpied, P., Dorfman, L.R. and Riebe, D. (2014) The effects of myofascial release with foam rolling on performance. Journal of Strength and Conditioning Research 28, 61-68.

Hodgson, D. D., Lima, C. D., Low, J. L. and Behm, D. G. (2018) Four weeks of roller massage training did not impact range of motion, pain pressure threshold, voluntary contractile properties or jump performance. International Journal of Sports Physical Therapy 13, 835-859.

Holm, S. (1979) A simple sequentially rejective multiple test procedure. Scandinavian Journal of Statistics 6, 65-70.

Jakobsen, M.D., Sundstrup, E., Andersen, C.H., Aagaard, P. and Andersen, L.L. (2013) Muscle activity during leg strengthening exercise using free weights and elastic resistance: effects of ballistic vs controlled contractions. Human Movement Science 32, 65-78.

Jakubiak, N. and Saunders, D.H. (2008) The feasibility and efficacy of elastic resistance training for improving the velocity of the Olympic Taekwondo turning kick. Journal of Strength and Conditioning Research 22, 1194-1197.

Janot, J.M., Auner, K.A., Emberts, T.M., Kaatz, R.M., Matteson, K.M., Muller, E.A. and Cook, M. (2013) The effects of BungeeSkate training on measures of on-ice acceleration and speed. International Journal of Sports Physiology and Performance 8, 419-427.

Jay, K., Sundstrup, E., Sondergaard, S.D., Behm, D., Brandt, M., Saervoll, C.A., Jakbosen M.D. andAndersen, L.L. (2014) Specific and cross over effects of massage for muscle soreness: randomized controlled trial. International Journal of Sports and Physical Therapy 9, 82-91.

Jones, A., Brown, L.E., Coburn, J.W. and Noffal, G.J. (2015) Effect of foam rolling on vertical jump performance. International Journal of Kinesiology and Sports Sciences 3, 38-42.

Joy, J.M., Lowery, R.P., Oliveira de Souza, E. and Wilson, J.M. (2016) Elastic Bands as a Component of Periodized Resistance Training. Journal of Strength and Conditioning Research 30, 2100-2106.

Junker, D.H. and Stoggl, T.L. (2015) The foam roll as a tool to improve hamstring flexibility. Journal of Strength and Conditioning Research 29, 3480-3495.

Kalichman, L. and Ben David, C. (2017) Effect of self-myofascial release on myofascial pain, muscle flexibility, and strength: A narrative review. Journal of Bodywork and Movement Therapies 21, 446-451.

Kay, A. D. and Blazevich, A. J. (2012) Effect of acute static stretch on maximal muscle performance: a systematic review. Medicine Science in Sports and Exercise 44 154-164.

Kelly, S., and Beardsley, C. (2016) Specific and cross-over effects of foam rolling on ankle dorsiflexion range of motion. International Journal of Sports Physical Therapy 11(4), 544-551.

Kisner, C. and Cloby, L.A. (2012) Therapeutic Exercise: Foundations and Techniques. 6th Ed. FA Davis Company Editions.

Le Roux, P. and Dupas, B. (1995) Decompression ou decoaptation de l'articulation coxo-femorale. Annales de Kinesitherapie 22, 233-234 [article in french].

Lorentz, D.S. (2014) Variable resistance training using elastic bands to enhance lower extremity strengthening. International Journal of Sports and Physical Therapy 9, 410-414.

MacDonald, G.Z., Button, D.C., Drinkwater, E.J. and Behm, D.G. (2014) Foam rolling as a recovery tool after an intense bout of physical activity. Medicine and Science in Sports and Exercise 46, 131-142.

MacDonald, G.Z., Penney, M.D., Mullaley, M.E., Cuconato, A.L., Drake, C.D., Behm, D.G. and Button, D.C. (2013) An acute bout of self-myofascial release increases range of motion without a subsequent decrease in muscle activation or force. Journal of Strength and Conditioning Research 27, 812-821.

McHugh, M.P., Johnson, C.D. and Morison, R.H. (2012) The role of neural tension in hamstring flexibility. Scandinavian Journal of Medicine and Science in Sports 22, 164-169.

Maisetti, O., Hug, F., Bouillard, K. and Nordez, A. (2012) Characterization of passive elastic properties of the human medial gastrocnemius muscle belly using supersonic shear imaging. Journal of Biomechanics 45, 978-984.

Mauntel, T.C.M. and Padua, D. (2014) Effectiveness of myofascial release therapies on physical performance measurements: A systematic review. Athletic Training and Sports Health Care 6, 189196.

Medeiros, D.M. and Lima, C.S. (2017) Influence of chronic stretching on muscle performance: Systematic review. Human Movement Science 54, 220-229.

Mikesky, A.E., Bahamonde, R.E., Stanton, K., Alvey, T. and Fitton, T. (2002) Acute effects of The Stick on strength, power, and flexibility. Journal of Strength and Conditioning Research 16, 446-450.

Mohr, A.R., Long, B.C. and Goad, C.L. (2014) Effect of foam rolling and static stretching on passive hip-flexion range of motion. Journal of Sport Rehabiltation 23, 296-299.

Monteiro, E.R., Cavanaugh, M.T., Frost, D.M. and Novaes, J.D. (2017) Is self-massage an effective joint range-of-motion strategy? A pilot study. Journal of Bodywork and Movement Therapies 21, 223-226.

Oesen, S., Halper, B., Hofmann, M., Jandrasits, W., Franzke, B., Strasser, E.M., Graf, A., Tschan, H., Bachl, N., Quittan, M., Wagner, K.H. and Wessner, B. (2015) Effects of elastic band resistance training and nutritional supplementation on physical performance of institutionalised elderly: A randomized controlled trial. Experimental Gerontology. 72, 99-108.

Okamoto, T., Masuhara, M. and Ikuta, K. (2014) Acute effects of self-myofascial release using a foam roller on arterial function. Journal of Strength and Conditioning Research 28, 69-73.

Page, P. (2012) Current concepts in muscle stretching for exercise and rehabilitation. International Journal of Sports and Physical Therapy 7, 109-119.

Page, P. and Ellenbecker, T.S. (2003) The scientific and clinical application of elastic resistance. Human Kineticks, Champaign, IL.

Park, S.Y., Kim, J.K. and Lee, S.A. (2015) The effects of a community-centered muscle strengthening exercise program using an elastic band on the physical abilities and quality of life of the rural elderly. Journal of Physical Therapy Science 27, 2061-2063.

Peacock, C.A., Krein, D.D., Antonio, J., Sanders, G.J., Silver, T.A. and Colas, M. (2015) Comparing Acute Bouts of Sagittal Plane Progressio Foam Rolling vs. Frontal Plane Progression Foam Rolling. Journal of Strength and Conditioning Research 29, 2310-2315.

Pearcey, G.E., Bradbury-Squires, D.J., Kawamoto, J.E., Drinkwater, E.J., Behm, D.G. and Button, D.C. (2015). Foam rolling for delayed-onset muscle soreness and recovery of dynamic performance measures. Journal of Athletic Training 50, 5-13.

R Core Team (2015) R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. Available from URL: https://www.R-project.org/

Rhea, M.R., Kenn, J.G. and Dermody, B.M. (2009) Alterations in speed of squat movement and the use of accommodated resistance among college athletes training for power. Journal of Strength and Conditioning Research 23, 2645-2650.

Roberts, J.M. and Wilson, K. (1999) Effect of stretching duration on active and passive range of motion in the lower extremity. British Journal of Sports Medicine 33, 259-263.

Roberts, S.P., Trewartha, G., England, M., Shaddick, G. and Stokes, K.A. (2013) Epidmiology of time-loss injuries in English community-level rugby union. BMJ Open 3, e003998.

Romero-Moraleda, B., La Touche, R., Lerma-Lara, S., Ferrer-Pena, R., Paredes, V., Peinado, A.B. and Munoz-Garcia, D. (2017) Neurodynamic mobilization and foam rolling improved delayed-onset muscle soreness in a healthy adult population: a randomized controlled clinical trial. Peer Journal 13, e3908.

Rosengart, M. (2013) PreHab exercise book for runners: Prepare to perform. 3rd Edition. CreateSpace Independent Publishing Platform.

Roylance, D.S., George, J.D., Hammer, A.M., Rencher, N., Gellingham, G.W., Hager, R.L. and Myrer, W.J. (2013) Evaluating acute changes in joint range-of-motion using self-myofascial release, postural alignment exercises, and static stretches. International Journal of Exercise Science 6, 310-319.

Sady, S.P., Wartman, M. and Blanke, D. (1982) Flexibility training: ballistic, static or proprioceptive neuromuscular facilitation? Archives in Physical Medicine and Rehabilitation 63, 261-263.

Schleip, R. (2003) Fascial plasticity-a new neurobiological explanation: Part 1. Journal of Bodywork and Movement Therapies 7, 11-19.

Schroeder, A.N. and Best, T.M. (2015) Is self myofascial release an effective preexercise and recovery strategy? A literature review. Current Sports Medicine Reports 14, 200-208.

Skarabot, J., Beardsley, C. and Stirn, I. (2015) Comparing the effects of self-myofascial release with static stretching on ankle range-of-motion in adolescent athletes. International Journal of Sports and Physical Therapy 10, 203-212.

Smith, C.J., Callister, R. and Lubans, D.R. (2011) A systematic review of strength and conditioning programmes designed to improve fitness characteristics in golfers. Journal of Sports Sciences 29, 933-943.

Soria-Gila, M.A., Chirosa, I.J., Bautista, I.J., Baena, S. and Chirosa, L.J. (2015) Effects of Variable Resistance Training on Maximal Strength: A Meta-Analysis. Journal of Strength Conditioning Research 29, 3260-3270.

Su, H., Chang, N. J., WU, W. L., Guo, L. Y., and Chu, I. H. (2017) Acute effects of foam rolling, static stretching, and dynamic stretching during warm-ups on muscular flexibility and strength in young adults. Journal of Sport Rehabilitation 26(6), 469-477.

Sullivan, K.M., Silvey, D.B., Button, D.C. and Behm, D.G. (2013) Rollermassager application to the hamstrings increases sit-and-reach range of motion within five to ten seconds without performance impairments. International Journal of Sports and Physical Therapy 8, 228-236.

Treiber, F.A., Lott, J., Duncan, J., Slavens, G. and Davis, H. (1998) Effects of Theraband and lightweight dumbbell training on shoulder rotation torque and serve performance in college tennis players. American Journal of Sports Medicine 26, 510-515.

Vigotsky, A.D., Lehman, G.J., Contreras, B., Beardsley, C., Chung, B. and Feser, E.H. (2015) Acute effects of anterior thigh foam rolling on hip angle, knee angle, and rectus femoris length in the modified Thomas test. Peer Journal 3, e1281.

Vinstrup, J., Calatayud, J., Jakobsen, M.D., Sundstrup, E., Jay, K., Brandt, M., Zeeman, P., Jorgensen, J.R. and Andersen, L.L. (2016) Electromyographic Comparison of Elastic Resistance and Machine Exercises for High-Intensity Strength Training in Patients With Chronic Stroke. Archives in Physical Medicine and Rehabilitation 97, 429-436.

Vigotsky A. D., Lehman, G J., Beardsley, C., Contreras, B., Chung, B., and Feser, E. H. (2016) The modified Thomas test is not a valid measure of hip extension unless pelvic tilt is controlled. Peer Journal 4, e2325.

Wilke, J., Krause, F., Vogt, L. and Banzer, W. (2016) What Is Evidence-Based About Myofascial Chains: A Systematic Review. Archives in Physical Medicine and Rehabilitation 97, 454-461.

Wyland, T.P., Van Dorin, J.D. and Reyes, G.F. (2015) Postactivation Potentation Effects From Accommodating Resistance Combined With Heavy Back Squats on Short Sprint Performance. Journal of Strength and Conditioning Research 29, 3115-3123.

Aymeric Guillot (1,2) ([mail]), Yann Kerautret (2,3), Florian Queyrel (2), William Schobb (2) and Franck Di Rienzo (2)

(1) Institut Universitaire de France, Paris; (2) Univ Lyon, Universite Claude Bernard Lyon 1, Laboratoire Interuniversitaire de Biologie de la Motricite (LIBM), Villeurbanne, France; (3) CAPSIX, 69450, Saint-Cyr au Mont d'Or, France.

Received: 30 July 2018 / Accepted: 09 January 2019 / Published (online): 11 February 2019

Aymeric GUILLOT

Employment

Professor at the University Claude Bernard Lyon 1.

Degree

PhD

Research interest

Mental processes and motor performance.

E-mail: aymeric.guillot@univ-lyon1.fr

Yann KERAUTRET

Employment

PhD Student at the University Claude Bernard Lyon 1.

Degree

Master degree

Research interest

Self-myofascial release.

E-mail: yannkerautret@gmail.com

Florian QUEYREL

Employment

Master Student at the University Claude Bernard Lyon 1.

Degree

Master degree

Research interest

Self-myofascial release, Physical and athletic training.

E-mail: florianqueyrel@orange.fr

William SCHOBB

Employment

Master Student at the University Claude Bernard Lyon 1.

Degree

Master degree

Research interest

Self-myofascial release, Physical and athletic training.

E-mail: william.schob@live.fr_

Franck Di RIENZO

Employment

Associate Professor at the University Claude Bernard Lyon 1.

Degree

PhD

Research interest

Mental processes and motor performance.

E-mail: franck.di-rienzo@univ-lyon1.fr

([mail]) Aymeric Guillot

Univ Lyon, Universite Claude Bernard Lyon 1, Laboratoire Interuniversitaire de Biologie de la Motricite (LIBM), EA7424, F69622, Villeurbanne, France.

Caption: Figure 1. Flow-Chart of the experimental design (Panel A) and foam rolling procedures for each muscle (Panel B). FR = Foam Rolling.

Caption: Figure 2. Flow-chart of the experimental design (Panel A) and joint distraction with elastic bands training procedures for each muscle (Panel B). EBT = Elastic Band Training.

Caption: Figure 3. Side split performance measures before and after the foam rolling intervention. The figure shows the median and quartile values. The initial level of performance was comparable in the three groups. Only significant gains in ROM observed during post-hoc tests are displayed. ** = p<0.01.

Caption: Figure 4. Range of motion before and after the foam rolling intervention. The figure shows the median and quartile values. Only significant differences in ROM between the pretest and the post-test are displayed. # p = 0.06, * p < 0.05, ** p < 0.01, *** p < 0.001.

Caption: Figure 5. Performance gains before and after the intervention. The figure shows the median and quartile values. Only significant performance gains between the pretest and the post-test are displayed. ** p < 0.01, *** p < 0.001.
Table 1. Anthropometric characteristics of the participants.

              Size (m)             Mass (kg)

Exp. 1   1.79 ([+ or -].06)   87.5 ([+ or -]11.2)
         1.81 ([+ or -].07)   88.6 ([+ or -]15.4)

Exp. 2   1.78 ([+ or -].09)   89.7 ([+ or -]17.6)
         1.80 ([+ or -].08)   88.3 ([+ or -]14.5)

         Body fat percentage

Exp. 1   15.6 ([+ or -]6.4)
         16.3 ([+ or -]8.6)

Exp. 2    17 ([+ or -]5.3)
         14.6 ([+ or -]7.8)

Table 2. Raw stretching performance data (mean [+ or -] sd). Values
are in degree.

Side split

                  Control                  FR20

Pre-test     112 [+ or -] 8.21     105.8 [+ or -] 11.83
Post-test   113.8 [+ or -] 10.21   123.5 [+ or -] 10.05

Active straight leg raising of the right hip

                  Control                  FR20

Pre-test     78.5 [+ or -] 5.91    74.8 [+ or -] 11.12
Post-test    79.1 [+ or -] 7.10     88.8 [+ or -] 7.13

Active straight leg raising of the left hip

                  Control                  FR20

Pre-test     78.2 [+ or -] 8.76    77.8 [+ or -] 11.01
Post-test    78.3 [+ or -] 7.86     87 [+ or -] 10.03

Active flexed leg raising of the right hip

                  Control                  FR20

Pre-test    90.8 [+ or -] 12.15    82.4 [+ or -] 11.42
Post-test    89 [+ or -] 10.67      96.6 [+ or -] 5.79

Active flexed leg raising of the left hip

                  Control                  FR20

Pre-test    91.9 [+ or -] 12.22    83.5 [+ or -] 10.10
Post-test   91.8 [+ or -] 10.89      95 [+ or -] 8.27

Active extension of right hip

                  Control                  FR20

Pre-test    176.9 [+ or -] 7.04    172.8 [+ or -] 5.26
Post-test   177.8 [+ or -] 5.94    189.9 [+ or -] 5.42

Active extension of left hip

                  Control                  FR20

Pre-test    178.3 [+ or -] 8.05    173.1 [+ or -] 5.32
Post-test    179 [+ or -] 5.35     188.6 [+ or -] 5.05

Active extension of right knee

                  Control                  FR20

Pre-test     50.9 [+ or -] 9.26     64 [+ or -] 17.32
Post-test    52.6 [+ or -] 9.28    57.9 [+ or -] 16.44

Active extension of left knee

                  Control                  FR20

Pre-test     50.1 [+ or -] 9.38    67.9 [+ or -] 19.72
Post-test    52.2 [+ or -] 8.09    59.1 [+ or -] 17.92

Active dorsiflexion of right ankle

                  Control                  FR20

Pre-test     67.8 [+ or -] 4.36     70.1 [+ or -] 4.28
Post-test    71.7 [+ or -] 4.13     71.5 [+ or -] 4.64

Active dorsiflexion of left ankle

                  Control                  FR20

Pre-test     71.1 [+ or -] 3.47     71.7 [+ or -] 3.65
Post-test    73.8 [+ or -] 2.69     71.6 [+ or -] 4.19

Side split

                    FR40

Pre-test    108.8 [+ or -] 14.34
Post-test   126.8 [+ or -] 14.34

Active straight leg raising of the right hip

                    FR40

Pre-test     73 [+ or -] 11.32
Post-test    89.2 [+ or -] 8.79

Active straight leg raising of the left hip

                    FR40

Pre-test     72.8 [+ or -] 9.94
Post-test   88.5 [+ or -] 10.56

Active flexed leg raising of the right hip

                    FR40

Pre-test    84.2 [+ or -] 10.68
Post-test   101.1 [+ or -] 6.06

Active flexed leg raising of the left hip

                    FR40

Pre-test     84.4 [+ or -] 9.55
Post-test   100.8 [+ or -] 8.32

Active extension of right hip

                    FR40

Pre-test     173 [+ or -] 5.45
Post-test   188.1 [+ or -] 6.95

Active extension of left hip

                    FR40

Pre-test    175.4 [+ or -] 5.08
Post-test   188.9 [+ or -] 5.15

Active extension of right knee

                    FR40

Pre-test    59.5 [+ or -] 10.98
Post-test    53 [+ or -] 12.65

Active extension of left knee

                    FR40

Pre-test    58.6 [+ or -] 16.43
Post-test   51.5 [+ or -] 14.09

Active dorsiflexion of right ankle

                    FR40

Pre-test     72.5 [+ or -] 7.38
Post-test    73.9 [+ or -] 4.58

Active dorsiflexion of left ankle

                    FR40

Pre-test      74 [+ or -] 6.81
Post-test    73.9 [+ or -] 6.50

Table 3. Performance gains after the foam rolling (FR) intervention.

                                                  Control Group

                                          Performance gains     P

Side Split                                  1.80[degrees]      0.67
Active straight leg raising--Right side     0.60[degrees]      0.84
Active straight leg raising--Left side      0.10[degrees]      0.98
Active flexed leg raising--Right side       -1.80[degrees]     0.73
Active flexed leg raising--Left side        -0.10[degrees]     0.98
Hip Extension--Right side                   0.90[degrees]      0.76
Hip Extension--Left side                    0.70[degrees]      0.82

                                               [FR.sub.20] group

                                          Performance gains      P

Side Split                                  17.70[degrees]     0.002
Active straight leg raising--Right side     14.00[degrees]     0.004
Active straight leg raising--Left side      9.20[degrees]      0.060
Active flexed leg raising--Right side       14.20[degrees]     0.004
Active flexed leg raising--Left side        11.50[degrees]     0.010
Hip Extension--Right side                   17.10[degrees]     0.001
Hip Extension--Left side                    15.50[degrees]     0.001

                                                [FR.sub.40] group

                                          Performance gains      P

Side Split                                  18.00[degrees]     0.005
Active straight leg raising--Right side     6.20[degrees]      0.002
Active straight leg raising--Left side      15.70[degrees]     0.003
Active flexed leg raising--Right side       16.90[degrees]     0.001
Active flexed leg raising--Left side        16.40[degrees]     0.001
Hip Extension--Right side                   15.10[degrees]     0.001
Hip Extension--Left side                    13.50[degrees]     0.001

Table 4. Raw stretching performance data (mean [+ or -] sd). Values
are in degree.

                              Front split

                     EBT                   Control

Pre-test    111.69 [+ or -] 12.24   107.4 [+ or -] 15.67
Post-test   115.07 [+ or -] 11.73   106.95 [+ or -] 16.10

                             Sit and reach

                     EBT                   Control

Pre-test     4.73 [+ or -] 8.55       4.5 [+ or -] 6.68
Post-test    6.07 [+ or -] 8.89      4.35 [+ or -] 6.98

                           Seated side split

                     EBT                   Control

Pre-test    150.30 [+ or -] 17.57   140.85 [+ or -] 13.54
Post-test   151.5 [+ or -] 19.93    141.4 [+ or -] 12.84

                      Side split against the wall

                     EBT                   Control

Pre-test    149.84 [+ or -] 16.69   141.90 [+ or -] 13.73
Post-test   149.69 [+ or -] 17.57   141.45 [+ or -] 14.24
COPYRIGHT 2019 Journal of Sports Science and Medicine
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2019 Gale, Cengage Learning. All rights reserved.

Article Details
Printer friendly Cite/link Email Feedback
Title Annotation:Research article
Author:Guillot, Aymeric; Kerautret, Yann; Queyrel, Florian; Schobb, William; Rienzo, Franck Di
Publication:Journal of Sports Science and Medicine
Article Type:Report
Date:Mar 1, 2019
Words:10449
Previous Article:Epigenetic Status of The Human MMP11 Gene Promoter is Altered in Patellar Tendinopathy.
Next Article:Effects of Vibration and Non-Vibration Foam Rolling on Recovery after Exercise with Induced Muscle Damage.
Topics:

Terms of use | Privacy policy | Copyright © 2019 Farlex, Inc. | Feedback | For webmasters