Muscle timing and activation patterns during two movement screening tests in subjects with and without low back pain.
Low back pain (LBP) is one of the most common conditions experienced by the majority of society. In the United States, LBP is one of the top five reasons for physician office visits with approximately 19 million visits reported in 2001 (Deyo, Mirza, & Martin, 2006; Panel on Musculoskeletal Disorders and the Workplace, 2001). Lifetime prevalence has been reported to be between 60% and 90% (Anderson, 1991; Waddell, 1987) and at any given time 6.8% of the world's population is affected by LBP (Cox, 2011). According to Patel and Ogle (2000), 50% of the active work force will experience symptoms related to LBP annually. It is one of the principal causes of absenteeism from work and daily activity impairment (van Dieen, Selen, & Cholewicki, 2003). One in five individuals with LBP report substantial limitations in activity (Von Korff & Saunders, 1996). After an acute episode, approximately 33% will report persistent back pain of at least moderate intensity during the following year (Von Korff & Saunders, 1996). Further, 10% of all patients suffering from LBP will experience disability lasting greater than three months (Woby, Watson, Roach, & Urmston, 2004).
Individuals with back pain were found to have trunk extensor weakness, excessive fatigability and poor lumbar muscle endurance (Pitcher, Behm, & MacKinnon, 2008; Taimela, Kankaanpaa, & Airaksinen, 1998). Low back pain has also been shown to negatively affect maximum voluntary muscle activation, through neuromuscular inhibition and/or altered motor control patterns of the trunk (O'Sullivan, Phyty, Twomey, & Allison, 1997; Richardson & Jull, 1995; Zedka, Prochazka, Knight, Gillard, & Gauthier, 1999).
In order to identify appropriate strengthening exercises, many studies have focused on muscle activity levels as opposed to understanding the muscle firing sequence and how it may differ in individuals with back pain. Electromyography (EMG) studies of the trunk musculature found that individuals with LBP displayed differences in muscle group amplitudes/activation levels that could not be explained by postural asymmetries (Dolce & Raczynski, 1985; Lariviere, Gagnon, & Loisel, 2000). Bullock-Saxton, Janda, and Bullock (1994) found that subjects with LBP experienced a delay in gluteus maximus firing while prone and gluteus medius firing while sidelying. Irregular firing patterns may lead to compensatory substitutions which reduce the effectiveness of stabilizing muscles (Danneels et al., 2002). Subjects with LBP also produced significantly lower force values (during isometric contraction) in the lumbar iliocostalis and the longissimus than those without pain (Candotti et al., 2008).
The prone straight leg raise (PSLR) and sidelying hip abduction (SHA) movement tests are frequently used to screen patients with low back and/or pelvic dysfunction (Davis, Bridge, Miller, & Nelson-Wong, 2011). Individuals with these dysfunctions seem to display altered movement patterns, making this type of screen appropriate. SHA may be useful in predicting low back pain (LBP) development during prolonged standing tasks (Nelson-Wong, Flynn, & Callaghan, 2009). It is important to understand normal firing patterns in order to correctly identify muscle dysfunction and choose effective treatment interventions (Vogt & Banzer, 1997). Therefore, the purpose of this study was to examine if differences exist in hip and trunk muscle activation and firing patterns during 2 movement screening tests in individuals with low LBP and healthy controls. Based on previous literature, we hypothesized that back muscle onset times and muscles firing patterns would differ between those with and without LBP.
Twenty-two healthy active subjects serving as a control group (11 males, 11 females; mean [+ or -] SD age, 27.2 [+ or -] 4.6 years; body mass index, 24.7 [+ or -] 4.9 kg/[m.sup.2]) and 12 subjects with LBP (5 males, 7 females; mean [+ or -] SD age, 44.4 [+ or -] 14.6 years; body mass index, 29.7 [+ or -] 10.3 kg/[m.sup.2]) volunteered to participate in this study. All subjects were 18 years of age or older and completed an informed consent form that described the testing protocol, which was approved by the University of Maryland Eastern Shore Institutional Review Board for protection of human subjects. Female subjects were excluded if they were currently pregnant or gave birth within the last 2 years.
The control group was recreationally active and participated in physical activity for an average of 3.5 hours per week. Subjects were in good general health and reported no symptoms of injury at the time of testing, no back or lower extremity pain for the past 6 months, and no history of back or lower extremity surgery. Subjects with low back pain were recruited from local physical therapy clinics and accepted for the study if they (1) reported that the back pain began within the last two months; (2) described a current level of pain 3 on a (0 to 10) visual analog scale; and (3) were referred to physical therapy by a physician or self-referred. Subjects with LBP were excluded if any of the following were present: (1) a history of back or lower extremity surgery; (2) signs of nerve root compression (2 or more of the following: positive straight leg raise test at an angle less than 45[degrees] or diminished lower extremity strength, sensory function, or deep tendon reflexes); and (3) evidence of serious pathology (e.g., acute spinal fracture, tumor, infection, etc).
General Practice Physical Activity Questionnaire (GPPAQ)
The GPPAQ provides a simple, four-level Physical Activity Index (PAI) reflecting an individual's current physical activity level. The instrument is intended for adults (16-74 years of age) and is a simple tool, requiring 30 seconds to complete. The GPPAQ has been shown to have good face and construct validity (Khaw et al., 2006). Subjects in the control group were asked to complete the GPPAQ in order to better understand their physical activity level in terms of their job and the type and amount of aerobic exercise regularly performed.
The visual analog scale (VAS) has been shown to be a valid and reliable instrument used to measure intensity of pain (McCormack, Horne, & Sheather, 1988; Price, McGrath, Rafii, & Buckingham, 1983). A 10-cm visual scale, with written descriptors at 0 ("no pain") and 10 ("maximum pain"), was used to understand pain intensity and determine participation eligibility. Subjects with LBP were asked to rate their current pain intensity and describe the current pain location.
Subjects attended one test session. During this time demographic data was collected, questionnaires completed, and subjects were assessed for the movement tests under investigation. Testing was performed on the dominant lower extremity or, in subjects with LBP, the pain dominant or movement impaired lower extremity. The EMG procedure consisted of electrode placement, practice and familiarization, and muscle onset timing assessment.
Subjects were prepared for electrode placement. Alcohol was used to cleanse the skin and reduce tissue impedance. Bipolar surface electrodes (Noraxon USA, Inc; Scottsdale, AZ) were placed on the selected muscles for each test, according to a basic understanding of surface anatomy (Greenman, 2003; Kendall, 2005). All of the posterior trunk and hip/thigh muscles (primarily responsible for the movement under consideration) accessible for assessment with surface EMG (Konrad, 2006) were investigated. Electrodes were silver-silver chloride pre-gelled with a diameter of 1 cm and inter-electrode distance of 2 cm. The same examiner, a physical therapist with approximately 14 years of clinical experience and a board certified orthopedic clinical specialist, positioned the electrodes on all subjects. Each electrode was connected to a Noraxon Telemyo 2400T G2 transmitter (Noraxon USA, Inc; Scottsdale, AZ). The sampling rate was 1500 Hz. All raw myoelectric signals were pre-amplified (overall gain, 500). The common mode rejection ratio was >100 dB, the signal-to-noise ratio was <1 [micro]V RMS baseline noise, and filtered to produce a bandwidth of 10-500 Hz.
For both movement tests, the same trunk muscles (lumbar multifidus and lumbar erector spinae) were recorded on both sides of the torso. The lumbar multifidus electrodes were placed 2 cm lateral to the L5 spinous process. Lumbar erector spinae electrodes were placed 4 cm lateral to the L3 spinous process. The lower extremity muscles differed for each movement test. During the PSLR, the Gluteus Maximus electrodes were placed 4 cm inferior to the posterior superior iliac spine. The medial and lateral hamstring electrodes were placed at the mid-thigh level, between the gluteal fold and the respective femoral condyle. During SHA, the tensor fascia latae electrodes were placed at the mid-point of an imaginary line between the greater trochanter and the anterior superior iliac spine (ASIS). The Gluteus Medius electrodes were applied 2.5 cm posterior to the midpoint of the line bisecting the ASIS and greater trochanter.
All electrodes were aligned parallel to the fiber direction of the target muscle. Correct electrode placement was verified by EMG signal analysis (visual inspection) during the motion test under consideration. This information was also used to ensure that a true baseline was maintained at rest. A reference electrode was placed along the shaft of the most palpable rib posteriorly, on the right mid-axillary line.
All subjects were screened to ensure they were able to perform each movement test. The test leg was identified and each subject was familiarized with the desired movement (verbally and visually) and practiced the motion twice. Corrective feedback was provided, if needed. With EMG equipment, each subject performed 2 trials for reliability and 2 trials for timing analysis, for each movement test. A standardized set of computer generated voice commands were used to synchronize the data collection process. Upon command, subjects moved into the desired position and held that position for 3 seconds. Subjects rested for 1 minute between trials.
The prone straight leg raise was the first movement test analyzed. Subjects were positioned their stomachs with their knees extended and ankles off the edge of the table. From this position, maximal hip extension was performed (Figure 1A). The next movement test analyzed was sidelying hip abduction. For this movement test, subjects were positioned on his or her non-test side with the test leg in neutral, resting on a pillow, with the knee extended. From this position, maximal hip abduction was performed (Figure 1B).
Raw EMG data were converted from analog to digital at 1500 Hz. The raw signals were rectified, smoothed, and reduced for cardiac artifact. Activation of the different muscles was determined for each movement test. We analyzed a 5 second window starting from the point where the subject was given the verbal command to contract. A muscle was considered to be activated when the signal surpassed the trigger level of 3 standard deviations beyond the baseline activity level at the beginning of the concentric phase of the motion. This method sets activation at a higher threshold and is considered to be a reliable technique (Bolgla, Malone, Umberger, & Uhl, 2010; Di Fabio, 1987). The point in time when each muscle reached this activity level was determined. If a muscle did not reach this level, the onset time was coded as 5 seconds. These measures of time were averaged for each muscle during both movement tests.
The statistical analysis was performed using Statistical Package for the Social Sciences, version 19.0 (SPSS Inc, Chicago, IL). An intraclass correlation coefficient (ICC) was used to determine same day test-retest reliability of the EMG recordings. The individual mean muscle onset times were averaged, across the group, to determine overall mean onset time for each muscle. From this data, the firing patterns for the 2 movement tests (PSLR and SHA) were established. A 1-way analysis of variance (ANOVA), with age as a covariate, was applied for each muscle to identify differences between groups. This was performed for each movement test.
Prone Hip Extension
During prone hip extension, Vogt and Banzer (1997) showed that in asymptomatic individuals, the ipsilateral erector spinae was recruited prior to the hamstrings. During the same motion, the gluteus maximus was the last muscle, within the muscles assessed, to be activated (Lehman, Lennon, Tresidder, Rayfield, & Poschar, 2004; Sakamoto et al., 2009; Vogt & Banzer, 1997). Results from our study revealed a similar activation pattern for subjects without LBP. The gross recruitment pattern began with the contralateral trunk extensors, followed by the ipsilateral trunk extensors, and finally the gluteus maximus. The immediate activation of the contralateral trunk muscles may initiate a stabilization process and balance the force required to move the limb on the opposite side of the body.
We found that this pattern was generally reversed in subjects with LBP as the recruitment process moved from a distal to proximal direction, with the exception of the gluteus maximus. In both groups, the gluteus maximus was the last muscle to fire. However, when comparing gluteus maximus activation times between groups, the onset time was significantly longer in subjects with LBP. This delay in activation of the gluteus maximus may have occurred secondary to inhibition of the stabilizing trunk musculature. Danneels et al. (2002) discussed how pain, pain avoidance and deconditioning may contribute to a reduction in back muscle EMG activity levels in subjects with LBP.
Sidelying Hip Abduction
When asymptomatic individuals performed SHA, the gluteus medius and tensor fascia latae were clinically observed to become active prior to the ipsilateral erector spinae, with the GM firing first (Greenman, 2003). Our results for sidelying hip abduction showed that subjects with and without low back pain displayed a similar muscle firing pattern, recruiting the lower extremity prior to the low back musculature. However, subjects with low back pain displayed a significant delay in the onset times for all of the back musculature examined. Although not found to be statistically different, subjects with low back pain displayed a mean delay of gluteus medius activation by more than one second. This delay in gluteus medius activation, possibly due to inhibition of the back musculature, may be clinically significant and could lead to abnormal movement patterns. Previous research has identified gluteus medius weakness as a factor that contributes to lower extremity injury via altered joint loading patterns and reduced motor control (Fulkerson, 2002; Powers, 2003).
The sidelying hip abduction screening tool performed moderately well in predicting those who are at risk for developing low back pain during prolonged standing (Nelson-Wong et al., 2009). This motion has also been show to be effective in activating the gluteus medius (Bolgla & Uhl, 2005; Distefano, Blackburn, Marshall, & Padua, 2009; Ekstrom, Donatelli, & Carp, 2007).
The same day test-retest ICCs for the EMG recordings from each muscle during each movement test are provided in Tables 1 and 2. These data suggest moderate to high reliability across trials for all muscles during each movement test. The only exception identified was the ipsilateral erector spinae during the PSLR, which was less reliable.
During the PSLR movement test, subjects with LBP activated the extremity muscles earlier than the back musculature. In healthy subjects, this pattern was reversed. In both groups, the gluteus maximus was the last muscle to be recruited. During SHA, the recruitment patterns were similar for both groups (extremity muscles fired before trunk musculature).
Significant differences in muscle onset timing were identified during both the PSLR and SHA tests. Compared to controls, subjects with LBP displayed a significantly greater gluteus maximus (P=.001) and ipsilateral erector spinae (P=.037) activation times during the PSLR (Table 3). Subjects with LBP also demonstrated significantly greater trunk muscle activation times (Pd".002), for all trunk muscles, during SHA (Table 4).
Muscle onset timing data and recruitment sequence for the PSLR and SHA are summarized in Tables 3 and 4, respectively. Subjects with LBP described their current pain intensity (mean [+ or -] SD) as 4.1 [+ or -] 1 cm on the VAS. Forty-one percent of the subjects with LBP reported having current pain in the central low back, 25% described pain in the right low back and right posterior thigh, 17% had pain in the left low back, and 17% had pain in the left low back and left posterior thigh.
The main objective in this study was to examine the differences in muscle onset timing and firing patterns during two frequently used screening tests in individuals with and without LBP. Significant differences in muscle onset times were identified between the two groups. During both movement tests, activation of the spine musculature was delayed in subjects with LBP. In addition, during the PSLR, subjects with LBP experienced a significant delay in gluteus maximus and ipsilateral erector spinae firing with a general reversal of muscle group recruitment patterns.
The movement tests examined in this study were chosen because they are commonly used by physical therapists to screen patients with low back and/or pelvic dysfunction. The quantity and quality of motion is assessed as well as any movement substitutions, secondary to abnormal muscle recruitment and/or symptom changes. Differences in muscle firing patterns have been linked to low back pain (LBP) and it has been suggested that clinicians should measure not only the strength, but also consider the sequence of trunk muscle activation (D'Orazio, 1993; Greenman, 2003).
When using the PSLR as a screening tool for individuals with low back pain, it is important to recognize that the gluteus maximus is expected to fire last and that palpation should be used to assess for muscular inhibition. Therapists should consider palpation of the lumbar musculature and gluteus maximus in order to identify gross side-to-side inhibition asymmetries while observing for any movement substitutions. When using SHA as a screening tool for individuals with low back pain, it is important to recognize that that the low back musculature (paraspinals and multifidii), on both sides of the trunk, may be dysfunctional. During this test, therapists should consider palpating both sides of the trunk musculature while simultaneously observing for any abnormal movement patterns. In patients with LBP, abnormal firing patterns may lead to compensatory substitutions which reduce the ability of the stabilizing muscles to perform optimally (Danneels et al., 2002). Several authors agree that the most common pathologic substitution, during the SHA, seems to be a delay in activation of the gluteus medius (Bruno & J., 2007; Bullock-Saxton et al.,1994; Greenman, 2003). Hodges and Richardson (1998) concur and demonstrated that in patients with LBP, the normal proximal to distal muscle activation pattern was reversed.
The prone straight leg raise and sidelying hip abduction screening tools are frequently used by physical therapists to assess for abnormal movement patterns and/or muscle inhibition. Compared to controls, subjects with low back pain showed a general recruitment pattern of extremity prior to trunk musculature during the PSLR. In addition, subjects with low back pain showed a significant delay in activation of the gluteus maximus and the ipsilateral paraspinal muscles. During the second test, SHA recruitment patterns were nearly identical for both groups as the lower extremity muscles were activated before the trunk. However, compared to controls, subjects with low back pain showed a significant delay in activation of all trunk musculature. Therefore, back muscle inhibition should be an immediate treatment consideration for individuals who are experiencing low back pain and test positive on either of the movement screening tests. Additional research is warranted in identifying treatment interventions that are most effective in restoring normal firing patters and muscle activation in individuals with low back pain.
The authors would like to thank Dr. Frank Rosenthal with McCready Foundation Inc., Dr. Lamont Thompson with Shore Health Systems, and Dr. Ray Moore III with Physical Therapy First for their assistance in data collection.
Anderson, G. (1991). The epidemiology of spinal disorders. (In Frymoyer JW, ed ed.). New York, NY: Raven Press.
Bolgla, L. A., Malone, T. R., Umberger, B. R., & Uhl, T. L. (2010). Reliability of electromyographic methods used for assessing hip and knee neuromuscular activity in females diagnosed with patellofemoral pain syndrome. J Electromyogr Kinesiol, 20(1), 142-147. doi: S1050-6411 (08)00197-1 [pii]0.1016/ j.jelekin.2008.11.008
Bolgla, L. A., & Uhl, T. L. (2005). Electromyographic analysis of hip rehabilitation exercises in a group of healthy subjects. J Orthop Sports Phys Ther, 35(8), 487-494.
Bruno, P. A., & J., B. (2007). An investigation into motor pattern differences used during prone hip extension between subjects with and without low back pain. Clinical Chiropractic, 10(2), 68-80.
Bullock-Saxton, J. E., Janda, V., & Bullock, M. I. (1994). The influence of ankle sprain injury on muscle activation during hip extension. Int J Sports Med, 15(6), 330-334. doi: 10.1055/s-2007-1021069
Candotti, C. T., Loss, J. F., Pressi, A. M., Castro, F. A., La Torre, M., Melo Mde, O., ... Pasini, M. (2008). Electromyography for assessment of pain in low back muscles. Phys Ther, 88(9), 1061-1067. doi: 10.2522/ ptj.20070146
Cox, J. M. (2011). Low Back Pain: Mechanism, Diagnosis and Treatment (7th ed.). Baltimore: Williams & Wilkins.
D'Orazio, B. (1993). Back pain rehabilitation. Boston: Andover Medical Publishers.
Danneels, L. A., Coorevits, P. L., Cools, A. M., Vanderstraeten, G. G., Cambier, D. C., Witvrouw, E. E., & De, C. H. (2002). Differences in electromyographic activity in the multifidus muscle and the iliocostalis lumborum between healthy subjects and patients with sub-acute and chronic low back pain. Eur Spine J, 11(1), 13-19.
Davis, A. M., Bridge, P., Miller, J., & Nelson-Wong, E. (2011). Interrater and intrarater reliability of the active hip abduction test. [Clinical Trial Research Support, Non-U.S. Gov't]. J Orthop Sports Phys Ther, 41(12), 953-960. doi: 10.2519/jospt.2011.3684
Deyo, R. A., Mirza, S. K., & Martin, B. I. (2006). Back pain prevalence and visit rates: estimates from U.S. national surveys, 2002. [Research Support, N.I.H., Extramural]. Spine (Phila Pa 1976), 31(23), 2724-2727. doi: 10.1097/ 01.brs.0000244618.06877.cd
Di Fabio, R. P. (1987). Reliability of computerized surface electromyography for determining the onset of muscle activity. Phys Ther, 67(1), 43-48.
Distefano, L. J., Blackburn, J. T., Marshall, S. W., & Padua, D. A. (2009). Gluteal muscle activation during common therapeutic exercises. [Comparative Study Research Support, Non-U.S. Gov't]. J Orthop Sports Phys Ther, 39(7), 532-540.doi:10.2519/ jospt.2009.2796
Dolce, J. J., & Raczynski, J. M. (1985). Neuromuscular activity and electromyography in painful backs: psychological and biomechanical models in assessment and treatment. [Comparative StudyReview]. Psychol Bull, 97(3), 502-520.
Ekstrom, R. A., Donatelli, R. A., & Carp, K. C. (2007). Electromyographic analysis of core trunk, hip, and thigh muscles during 9 rehabilitation exercises. J Orthop Sports Phys Ther, 37(12), 754-762. doi: 10.2519/jospt.2007.2471
Fulkerson, J. P. (2002). Diagnosis and treatment of patients with patellofemoral pain. [Review]. Am J Sports Med, 30(3), 447-456.
Greenman, P. E. (2003). Principles of manual medicine (3rd ed.). Philadelphia: Lippincott Williams & Wilkins.
Hodges, P. W., & Richardson, C. A. (1998). Delayed postural contraction of transversus abdominis in low back pain associated with movement of the lower limb. J Spinal Disord, 11(1), 46-56.
Kendall, F. P. (2005). Muscles : testing and function with posture and pain (5th ed.). Baltimore, MD: Lippincott Williams & Wilkins.
Khaw, K. T., Jakes, R., Bingham, S., Welch, A., Luben, R., Day, N., & Wareham, N. (2006). Work and leisure time physical activity assessed using a simple, pragmatic, validated questionnaire and incident cardiovascular disease and all-cause mortality in men and women: The European Prospective Investigation into Cancer in Norfolk prospective population study. Int J Epidemiol, 35(4), 1034-1043. doi: dyl079 [pii]10.1093/ije/dyl079
Konrad, P. (2006). The ABC of EMG (Vol. version 1.4). Scottsdale: Noraxon USA, Inc.
Lariviere, C., Gagnon, D., & Loisel, P. (2000). The comparison of trunk muscles EMG activation between subjects with and without chronic low back pain during flexion-extension and lateral bending tasks. [Comparative Study Research Support, Non-U.S. Gov't]. J Electromyogr Kinesiol, 10(2), 79-91.
Lehman, G. J., Lennon, D., Tresidder, B., Rayfield, B., & Poschar, M. (2004). Muscle recruitment patterns during the prone leg extension. BMC Musculoskelet Disord, 5, 3. doi: 10.1186/1471-2474-5-31471-2474-5-3 [pii]
McCormack, H. M., Horne, D. J., & Sheather, S. (1988). Clinical applications of visual analogue scales: a critical review. [Review]. Psychol Med, 18(4), 1007-1019.
Nelson-Wong, E., Flynn, T., & Callaghan, J. P. (2009). Development of active hip abduction as a screening test for identifying occupational low back pain. [Controlled Clinical Trial
Research Support, Non-U.S. Gov't]. J Orthop Sports Phys Ther, 39(9), 649-657. doi: 10.2519/jospt.2009.3093
O'Sullivan, P. B., Phyty, G. D., Twomey, L. T., & Allison, G. T. (1997). Evaluation of specific stabilizing exercise in the treatment of chronic low back pain with radiologic diagnosis of spondylolysis or spondylolisthesis. Spine (Phila Pa 1976), 22(24), 2959-2967.
Panel on Musculoskeletal Disorders and the Workplace, C. o. B. a. S. S. a. E., & National Research Council. (2001). Musculoskeletal Disorders and the Workplace: Low Back and Upper Extremities (1 ed.). Washington DC: National Academies Press.
Patel, A. T., & Ogle, A. A. (2000). Diagnosis and management of acute low back pain. [Review]. Am Fam Physician, 61(6), 1779-1786, 1789-1790.
Pitcher, M. J., Behm, D. G., & MacKinnon, S. N. (2008). Reliability of electromyographic and force measures during prone isometric back extension in subjects with and without low back pain. [Controlled Clinical Trial Research Support, Non-U.S. Gov't Validation Studies]. Appl Physiol Nutr Metab, 33(1), 52-60. doi: 10.1139/H07-132
Powers, C. M. (2003). The influence of altered lower-extremity kinematics on patellofemoral joint dysfunction: a theoretical perspective. [Review]. J Orthop Sports Phys Ther, 33(11), 639-646.
Price, D. D., McGrath, P. A., Rafii, A., & Buckingham, B. (1983). The validation of visual analogue scales as ratio scale measures for chronic and experimental pain. Pain, 77(1), 45-56.
Richardson, C. A., & Jull, G. A. (1995). Muscle control-pain control. What exercises would you prescribe? Man Ther, 7(1), 2-10. doi: 10.1054/ math.1995.0243
Sakamoto, A. C., Teixeira-Salmela, L. F., de Paula-Goulart, F. R., de Morais Faria, C. D., & Guimaraes, C. Q. (2009). Muscular activation patterns during active prone hip extension exercises. J Electromyogr Kinesiol, 79(1), 105-112. doi: S1050-6411(07)00117-4 [pii] 10.1016/j.jelekin.2007.07.004
Taimela, S., Kankaanpaa, M., & Airaksinen, O. (1998). A submaximal back extension endurance test utilising subjective perception of low back fatigue. Scand J Rehabil Med, 30(2), 107-112.
van Dieen, J. H., Selen, L. P., & Cholewicki, J. (2003). Trunk muscle activation in low-back pain patients, an analysis of the literature. [Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, P.H.S.Review]. J Electromyogr Kinesiol, 73(4), 333-351.
Vogt, L., & Banzer, W. (1997). Dynamic testing of the motor stereotype in prone hip extension from neutral position. Clin Biomech (Bristol, Avon), 72(2), 122-127. doi: S0268003396000551 [pii]
Von Korff, M., & Saunders, K. (1996). The course of back pain in primary care. [Research Support, U.S. Gov't, P.H.S.Review]. Spine (Phila Pa 7976), 27(24), 2833-2837; discussion 2838-2839.
Waddell, G. (1987). 1987 Volvo award in clinical sciences. A new clinical model for the treatment of low-back pain. [Review]. Spine (Phila Pa 7976), 72(7), 632-644.
Woby, S. R., Watson, P. J., Roach, N. K., & Urmston, M. (2004). Adjustment to chronic low back pain--the relative influence of fear-avoidance beliefs, catastrophizing, and appraisals of control. [Research Support, Non-U.S. Gov't]. Behav Res Ther, 42(7), 761-774. doi: 10.1016/S0005-7967(03)00195-5
Zedka, M., Prochazka, A., Knight, B., Gillard, D., & Gauthier, M. (1999). Voluntary and reflex control of human back muscles during induced pain. [Research Support, Non-U.S. Gov't]. J Physiol, 520 Pt 2, 591-604.
Department of Physical Therapy
University of Maryland Eastern Shore
Mike Lominac, PT, DPT
Department of Physical Therapy
University of Maryland Eastern Shore
Ryan Chase, PT, DPT
Department of Physical Therapy
University of Maryland Eastern Shore
Chin Yoon, PT, DPT
Department of Physical Therapy
University of Maryland Eastern Shore
TABLE 1 Within Subject Reliability For Each Muscle During The Prone Straight Leg Raise Muscle ICC SEM (ms) Contralateral Erector Spinae 0.90 293 Contralateral Multifidus 0.76 439 Ipsilateral Biceps Femoris 0.65 132 Ipsilateral Semitendinosus 0.65 180 Ipsilateral Multifidus 0.97 137 Ipsilateral Erector Spinae 0.39 899 Gluteus Maximus 0.96 295 Abbreviations: ICC, intraclass correlation coefficient; SEM, standard error of measurement; ms, milliseconds. TABLE 2 Within Subject Reliability For Each Muscle During Side Lying Hip Abduction Muscle ICC SEM (ms) Tensor Fascia Latae 0.77 439 Gluteus Medius 0.90 365 Ipsilateral Multifidus 0.93 501 Ipsilateral Erector Spinae 0.98 276 Contralateral Erector Spinae 0.94 493 Contralateral Multifidus 0.96 401 Abbreviations: ICC, intraclass correlation coefficient; SEM, standard error of measurement; ms, milliseconds. TABLE 3 Timing of Selected Muscles During The Prone Straight Leg Raise * Muscle Control (n=22) Under Sequence & Investigation Mean Onset Time Contralateral 1 720 [+ or -] 235 Erector Spinae Contralateral 2 738 [+ or -] 171 Multifidus Ipsilateral 3 744 [+ or -] 173 Biceps Femoris Ipsilateral 4 747 [+ or -] 262 Semitendinosus Ipsilateral 5 736 [+ or -] 227 Multifidus Ipsilateral 6 823 [+ or -] 264 Erector Spinae Gluteus 7 882 [+ or -] 180 Maximus Muscle LBP (n=12) P Under Sequence & Investigation Mean Onset Time Contralateral 5 1516 [+ or -] 1353 0.2 Erector Spinae Contralateral 4 1504 [+ or -] 1236 0.7 Multifidus Ipsilateral 1 756 [+ or -] 243 0.7 Biceps Femoris Ipsilateral 2 824 [+ or -] 272 0.1 Semitendinosus Ipsilateral 3 1363 [+ or -] 1207 0.3 Multifidus Ipsilateral 6 2064 [+ or -] 1121 0 Erector Spinae Gluteus 7 2810 [+ or -] 1885 0 Maximus * Values are expressed as mean [+ or -] SD milliseconds. TABLE 4 Timing of Selected Muscles During Side Lying Hip Abduction * Muscle Under Control (n=22) Investigation Sequence & Mean Onset Time Tensor Fascia 1 648 [+ or -] 126 Latae Gluteus Medius 2 648 [+ or -] 150 Ipsilateral 3 1086 [+ or -] 919 Multifidus Ipsilateral 4 977 [+ or -] 404 Erector Spinae Contralateral 5 2734 [+ or -] 1914 Erector Spinae Contralateral 6 1546 [+ or -] 1463 Multifidus Muscle Under LBP (n=12) P Investigation Sequence & Mean Onset Time Tensor Fascia 1 1282 [+ or -] 1333 0 Latae Gluteus Medius 2 1629 [+ or -] 1715 0 Ipsilateral 3 4176 [+ or -] 1283 < .001 Multifidus Ipsilateral 6 4887 [+ or -] 393 < .001 Erector Spinae Contralateral 5 4814 [+ or -] 490 0 Erector Spinae Contralateral 4 4431 [+ or -] 1295 < .001 Multifidus * Values are expressed as mean [+ or -] SD milliseconds.
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|Author:||Rabel, Michael; Chase, Ryan; Lominac, Mike; Yoon, Chin|
|Publication:||Journal of the National Society of Allied Health|
|Date:||Mar 22, 2013|
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