Description of movement patterns of young adults moving supine from the foot to the head of the bed.

Key Words: Bed mobility, Descriptions, Movement pattern, Variability.

Physical therapists often use visual observation[1-3] to distinguish between typical and atypical movements. Atypical movement patterns (MPs) are judged to be abnormal1 and trigger further evaluation and possible treatment. Latash and Anson[4] have argued against correcting movements of those persons from atypical populations, suggesting that these actions represent solutions to the problems presented by impairments. Until MPs of individuals from both typical populations and atypical populations (ie, those with Parkinson disease or amputations) have been described, arguments related to the treatment of persons with disabilities of functional movement are premature.

Numerous investigators have described MPs used by subjects without impairments performing routine daily activities such as rising from a bed,[5,6] rising from the floor,[7,8] standing up from a chair,[9,10] and rolling from a supine position to a prone position,[11] These investigators[5-8,11,12] videotaped subjects, divided the body into regions, and developed categorical descriptions for the MPs of each region. The descriptions could be used in the clinic because they are based on visual observation rather than measurement with expensive equipment.[7] Reports describing their use, however, have not appeared in the peer-reviewed literature. The results of these previous studies[6,7,9,11,12] have suggested that adults without impairments use a variety of MPs, and there are usually several combinations of movements that are most common within a particular age group,[5] VanSant[12] stated it is the potential for variability that characterizes normalcy.

Although physical therapists frequently evaluate tasks such as rolling and bed transfers, they rarely evaluate the task of moving supine from the foot to the head of the bed (scooting), even though patients are asked to scoot to achieve alignment in bed or to prepare for another activity. Although scooting is a transitional activity between tasks, it is a critical component required to successfully complete tasks, as well as a being task in itself. There have been no published descriptions of MPs used for the bed mobility task of scooting. A variety of scooting patterns most likely will be observed among persons without neuromuscular or musculoskeletal impairments.[2] Information regarding strategies typically used for scooting in bed could help physical therapists evaluate the task of scooting and design interventions for patients who have difficulty performing this task.[2,5-9,11] The purpose of this study was to describe the MPs used by young adults in supine scooting from the foot to the head of the bed.

Method

Subjects

Thirty-six adults, aged 19 through 44 years ([bar] X=23.8, SD=6.3), participated in our study. This sample was one of convenience and consisted of first-year physical therapist students at Thomas Jefferson University, Philadelphia, Pa. Prior to the study, all subjects reported that they were able to scoot in bed. Individuals who reported any acute or chronic medical conditions, neuromuscular or musculoskeletal impairments, limits placed on them by their physician, or pain that would limit bed mobility were excluded. Individuals were also excluded if they had undergone a physical therapy evaluation, received treatment to improve bed mobility, or had been involved in a descriptive analysis of bed mobility. The aim was to exclude subjects whose scooting strategy might be based on preconceived notions of how a person should move in bed. Each subject read and signed an informed consent form.

Equipment and Layout of the Videotaping Field

Figure 1 depicts the layout of the videotaping field. Two Panasonic AG450 S-VHS video cameras(*) mounted on tripods were used to record each subject's movements while scooting in bed. During data reduction, videotapes were viewed using Panasonic AG1960 videocassette recorders(*) and a 0.51-m (20-in) television monitor. A standard hospital bed measuring 2.12 m long, 0.89 m wide, and 0.72 m high, and covered with a fitted sheet, was used. The bed had no footboard and was in a flat position so that the surface was a smooth, horizontal plane. One camera was positioned perpendicular to the length of the bed, providing a right side view. The camera was positioned 1.92 m from the midpoint of the bed, with the bottom of the lens 1.48 m above the floor. The second camera was positioned perpendicular to the width of the bed, providing a view of the foot of the bed. This camera was positioned 1.77 m from the midpoint of the bed, and the bottom of the lens was 1.48 m above the floor. To identify each subject and individual trials, 2 flip charts with 27.9-cm-tall (11-in-tall) numbers were placed in a position to be viewed by both cameras.

[Figure 1 ILLUSTRATION OMITTED]

Procedure

The purpose and procedures of the study were explained to each subject. Female subjects wore a sports bra and gym shorts and male subjects wore gym shorts to allow good visibility of body movement. The subjects assumed the supine position parallel to the length of the bed with the right side of the body oriented toward the side-view Camera. Subjects were instructed: "Lie on your back with your arms at your side, legs straight, with your heels touching the foot of the bed." The subjects were then instructed, on the command "Ready, begin," to perform one scoot toward the head of the bed in any manner and at their own pace. If a subject did not follow the directions, the trial was repeated. After each trial, the subjects were instructed to return to the starting position. Videotaping started approximately 10 seconds prior to the first trial and continued until all 10 trials were videotaped.

Data Reduction

Each student researcher was randomly assigned to develop descriptive categories for 1 of 3 body regions. Two researchers viewed and described MPs for the axial region, one researcher viewed and described MPs of the upper extremities (UEs), and another researcher viewed and described MPs of the lower extremities (LEs). To avoid accommodation to each subject tie, to avoid anticipation of what the subject might do based on his or her previous scoot), the first trial of all subjects was viewed and the MPs were described for each body region, then the second trial of all subjects was viewed and the MPs were described for each body region, and so forth until all trials had been viewed and described. Both the side-view and the foot-view videotapes were used individually to describe MPs of all body regions. After the trial descriptions were written, each researcher compared similarities and differences within that respective body region. To develop the categories for each body region, similar trial descriptions were combined to form a smaller number of more general descriptions for each category. The researchers then reviewed the subject trials and categorized each trial.

Data Analysis

An experienced physical therapist with a background in neurological rehabilitation was trained by each researcher on how to classify each body region using the categorical descriptions that were developed. A random set of 50 trials was selected for the trained rater to view. The trained rater viewed the trials and classified each body region into a category. If less than 85% of exact agreement was found within the classifications of a body region with the ratings by the researcher, the descriptions were reviewed and refined to improve interrater agreement. A second set of 50 trials was randomly selected, and the process was repeated until 85% or greater of exact agreement was obtained for all body regions. Once interrater agreement was obtained, a kappa statistic[13,14] was calculated as a measure of reliability. The randomly selected set of 50 trials used to obtain interrater agreement was used to determine intrarater agreement for the researchers who developed the categorical descriptions.

Results

Reliability of Categorical Descriptions

Eighty-six percent interrater agreement was attained in the LE body region with the first randomly selected set of 50 trials. The initial measures of exact agreement found for the axial region and UEs were 82% and 76%, respectively. These percentages of exact agreement required that the categories be refined. Interrater agreement was determined again with a second set of randomly selected 50 trials. This repeat classification exceeded the criterion of 85% of exact agreement. The percentages of exact agreement and the kappa statistics are reported in Table 1. Intrarater agreement for the axial region, UEs, and LEs exceeded the criterion of 85% of exact agreement in each instance.

Table 1.

Percentages of Exact Agreement and Kappa Statistics (N=50 Trials)(a)

                              Axial     Upper       Lower
                              Region    Extremity   Extremity

Intrarater agreement (%)(b)   92.0      94.0        86.0
Interrater agreement (%)(c)   90.0      92.0        86.0
Kappa(c)                        .87       .90         .81

(a) Results were calculated based on a randomly selected set of 50 trials.

(b) Repeat classifications by the first rater.

(c) Classifications by the first and second raters.

Movement Patterns Used by Young Adults to Scoot From Foot to Head of Bed

Six MP categories were developed for the axial region, 8 MP categories were developed for the UEs, and 6 MP categories were developed for the LEs. The categories, descriptions, and frequency with which each category of movement appeared across trials are presented for each body region in Tables 2, 3, and 4.

Table 2.

Frequency Across Trials (N=340)(a) for Axial Region Component
Categories

Category        Description

Sit slide       Axial region flexes forward off the support surface
                  toward an upright sitting position, achieving at
                  least 45 [degrees] of flexion during the scoot.
                  The buttocks or lower trunk may or may not be
                  lifted.
Recline slide   Upper trunk flexes forward off the support surface
                  toward a sitting position, achieving a reclined
                  posture (<45 [degrees]). Buttocks or lower
                  trunk may or may not be lifted.
Bridge          Weight is transferred to the upper trunk and the
                  pelvis elevates, but the buttocks may or may not
                  lose contact with the support surface.
Rigid slide     Trunk exhibits minimal mobility, and the upper
                  trunk and pelvis remain in the same horizontal
                  plane.
Side bend       Alternating lateral flexion of axial region is seen
                  with or without buttocks contacting the support
                  surface.
Lateral roll    Rotation of axial region simultaneously brings one
                  buttock and shoulder or trunk of the support
                  surface prior to scooting. Head and trunk are
                  aligned.
Total

Category         Frequency (%)

Sit slide            37.7
Recline slide        20.0
Bridge               17.4
Rigid slide          14.1
Side bend             8.2
Lateral roll          2.6
Total               100.0

(a) Results were calculated based on 340 trials used for the creation of movement pattern categories.

Table 3.

Frequency Across Trials (N=340)(a) for Upper-Extremity
Component Categories

Category                      Description

Bilateral simultaneous hand   Both hands and/or wrists are placed on
  push                          support surface and push
                                simultaneously. No other part of
                                upper extremities contacts
                                support surface during push.
Bilateral simultaneous        The segments contacting the support
  upper-extremity push          surface of one upper extremity are
                                the same as the segments contacting
                                the support surface of the other
                                upper extremity. Contact segments
                                may include wrists, forearms,
                                elbows, arms, and/or shoulders. The
                                push occurs simultaneously.
Asymmetrical simultaneous     Different segments of the upper
  push                          extremities contact the support
                                surface. The push occurs
                                simultaneously.
Alternating push              First one upper extremity and then the
                                other upper extremity is used to
                                push. There may be asymmetry in the
                                segments of the upper extremity
                                contacting the surface.
Grasp and push                Both hands grasp sides of mattress
                                simultaneously, and the upper
                                extremities push using the elbow,
                                forearm, and/or hands.
Lift                          One or both upper extremities are
                                lifted off support surface during
                                scoot. If one upper extremity
                                remains in contact with support
                                surface, it does not participate.
No arm movement               Both upper extremities do not
                                participate in the scoot. Limbs drag
                                on support surface in either a
                                straight or bent position.
Cross-body push               One upper extremity crosses midline
                                and contacts support surface
                                beside opposite shoulder. The
                                other upper extremity performs a
                                push using the forearm, elbow, arm,
                                and/or shoulder.
Total

Category                           Frequency (%)

Bilateral simultaneous hand            37.9
  push
Bilateral simultaneous                 19.7
  upper-extremity push
Asymmetrical simultaneous              12.4
  push
Alternating push                       11.5
Grasp and push                          8.8
Lift                                    5.3
No arm movement                         3.5
Cross-body push                         0.9
Total                                 100.0

(a) Results were calculated based on 340 trials used for the creation of movement pattern categories.

Table 4.

Frequency Across Trials (N=340)(a) for Lower-Extremity
Component Categories

Category                   Description

Double push                Both lower extremities simultaneously
                             flex to bring the feet in contact with
                             the support surface. The feet then
                             simultaneously push on the surface.
Unilateral push and lift   One lower extremity is positioned in
                             flexion with the foot contacting and
                             pushing on the support surface. The
                             other lower extremity is lifted off
                             the surface during the scoot. The
                             leg returns to the surface at the end
                             of the scoot.
Unilateral push and drag   One lower extremity is positioned in
                             flexion, with the foot contacting and
                             pushing on the support surface. The
                             other lower extremity remains in
                             contact with the surface, with
                             the knee fully extended or slightly
                             flexed and the heel dragging on the
                             support surface throughout the scoot.
Step to push               First one lower extremity and then the
                             other lower extremity are flexed to
                             bring the feet in contact with the
                             support surface. Both feet
                             simultaneously push on the support
                             surface.
Bilateral leg drag         Both lower extremities maintain contact
                             with support surface throughout the
                             scoot and do not participate in the
                             movement. Slight knee flexion in one
                             or both knees may be present.
Alternating push           One knee is flexed, and the ipsilateral
                             foot pushes on the support surface.
                             Then, the other knee is flexed, and the
                             foot pushes on the support surface.
                             This sequence may be repeated with one
                             or both lower extremities.
Total

Category                           Frequency (%)

Double push                            40.3
Unilateral push and lift               28.3
Unilateral push and drag               19.7
Step to push                            8.5
Bilateral leg drag                      2.6
Alternating push                        0.6
Total                                 100.0

(a) Results were calculated based on 340 trials used for the creation of movement pattern categories.

Three hundred sixty-six trials were videotaped. Replacement trials were recorded for 6 subjects who did not initially follow the directions. Therefore, 6 extra trials were recorded. The data from one subject's trials were omitted because it became apparent that the subject was making deliberate efforts with each trial to scoot differently rather than naturally (the subject performed somersaults) (10 trials). Other trials were omitted for the following reasons: scooting more than once (9 trials), data missing due to a videotaping error (3 trials), not ending the scoot in the supine position (2 trials), scooting toward the foot of the bed (1 trial), and not starting in the correct position (1 trial). Thus, 26 trials were omitted, leaving 340 trials used for the creation of the categories.

The most common motion observed in the axial region, occurring in nearly 40% of the trials, involved the subject's axial region being lifted off the support surface toward an upright position. The most common MP for the UEs, occurring in approximately 40% of the trials, involved the subject placing both hands on the support surface and pushing simultaneously. The most frequently observed motion for the LEs, occurring in about 40% of the trials, involved both feet coming in contact with the support surface and pushing simultaneously.

Most Common Form of Scooting

Fifty-nine different combinations of MPs in the axial region, UEs, and LEs were exhibited in the 340 trials described. Nineteen of these MP combinations were seen in only 1 trial. Table 5 shows the frequencies of the most common MP combinations observed across trials. Only combinations appearing in greater than 4% of the trials are included in Table 5. One combination of composite body motion occurred almost 3 times more often than any other combination. This particular combination included the "sit slide," "bilateral simultaneous hand push," and "double push" MPs (Fig. 2). The pattern of assuming a relatively upright axial position and pushing with both hands occurred in 3 of the 4 most common MP combinations. The corresponding category titles are "sit slide" and "bilateral simultaneous hand push." The LE MPs varied among the "double push," the "unilateral push and drag" (Fig. 3), or the "unilateral push and lift" (Figs. 4 and 5) in the most prevalent MP combinations. Another common pattern included a "side bend" in the axial region, an "alternating push" of the UEs, and a "unilateral push and lift" of the LEs (Fig. 4).

[Figures 2, 3, 4 & 5 ILLUSTRATION OMITTED]

Table 5.

Four Most Common Movement Pattern Combinations Observed
Across 340 Trials (N=36)(a)

Axial        Upper-       Lower-
Region       Extremity    Extremity    Frequency
Pattern(b)   Pattern(c)   Pattern(d)   (%)

SS           BSHP         DP           21.2
SS           BSHP         UPD           7.3
SB           AP           UPL           5.3
SS           BSHP         UPL           4.7

(a) Results were calculated based on the number of subjects videotaped.

(b) SS=sit slide, SB=side bend.

(c) BSHP=bilateral simultaneous hand push, AP=alternating push.

(d) DP=double push, UPD=unilateral push and drag, UPL=unilateral push and lift.

Variability Within Subjects

Three subjects demonstrated the same MP combination across their 10 trials, and only 1 subject showed variation across all 10 trials. Twenty-three of the 36 subjects varied their axial region MP during their 10 trials of scooting. The remaining 13 subjects did not vary their axial region MP. Twenty-five of the 36 subjects demonstrated variability in UE motion across their 10 trials of scooting. The other 11 subjects demonstrated no variability in UE motion. Twenty-four subjects varied among the LE MP used during their 10 trials, and the remaining 12 subjects did not vary in LE motion.

Discussion

This article represents one in a growing series of studies of the performance of movements associated with functional tasks in individuals with and without disabilities. This work illustrates the range of strategies that can be used to perform tasks such as scooting. We believe that, by studying the solutions of many individuals of different ages, including those with disabling conditions, therapists can become informed of the range of movement strategies available to solve the movement problems inherent in common tasks of daily living. Through studies such as the one we report here, it is possible to understand the range of strategies used to perform these tasks and the factors that influence the selection of strategies among individuals of different ages and body dimensions as they function in a variety of environmental contexts.

VanSant's research on the movements young adults used to rise from a supine position to a standing position suggested that the most common MPs involved symmetrical movement of the trunk and all 4 extremities.[7] We also found symmetrical patterns to be most common among a similar age group when scooting in bed, because the most common MP combination involved the "sit slide," "bilateral simultaneous hand push," and "double push" MPs. In this MP combination, both the hands and feet push against the bed while the body is lifted against gravity. A characteristic of this MP combination is that it reduces friction of body parts sliding on the bed.

The "sit slide" MP may also reflect the subjects' preference for performing the task in an upright posture. This type of MP may occur because humans are usually upright when performing the majority of functional activities. The subjects may have flexed forward toward a sitting position to reduce friction, and thus increase comfort while scooting, and to right their head to view their environment better. The "bilateral simultaneous hand push" MP may be related to the position of the trunk. From the relatively uptight position, the hands were the only part of the UE that touched the support surface.

Similar to other tasks such as rising from a bed,[5,6] rising from a chair,[9,10] and rising from the floor,[7,8] a large amount of variability among persons exists in scooting. We believe that, to help people with disability develop a set of age-appropriate MPs that can be used to solve problems presumably caused by impairments, physical therapists should be aware of and appreciate the great variability that individuals without disability use. In our view, some populations of individuals with impairments may differ from individuals without impairments, not in the pattern of movement used, but in the absence of variability.

Further research is needed to understand the stability and force requirements of the different strategies used to accomplish the task of moving supine from the foot to the head of the bed (scooting).[9] These requirements have implications for retraining skills in patients with neuromuscular or musculoskeletal impairments. For example, we believe it is possible that an individual with a long-leg cast for a fractured left femur may have commonly used a "double push" MP before sustaining the fracture, but the physical therapist will likely chose the "unilateral push and drag" MP as a compensatory strategy for scooting.

There are limitations that may have affected the outcome of this study. Thirty-six first-year physical therapist students from Thomas Jefferson University were solicited and volunteered to participate in this study. This sample was one of convenience with little cultural diversity among subjects. To maximize the external validity, subjects should have been more widely selected from the population of young adults.

Two camera views were used to collect data: one camera provided a view of the foot of the bed, and the other camera provided a right side view of the subjects. A third camera providing a left side view would have eliminated any uncertainties regarding the left UE movement during the scoot when it was obscured by the trunk or LEs.

Videotaping observational data has become an efficient and widely used method for recording behavior.[1-3] There are, however, a number of problems inherent in using videotaped data. Introducing video cameras to the observational setting increases the threat to external validity.[3] Subjects may behave differently because they are being observed. Some subjects become shy, whereas other subjects become flamboyant.[3] Because we suspected flamboyance, one subject was eliminated from our shady.

Movements associated with function, such as scooting, are based on the goals of the task and the environmental context in which the action takes place.[1] In order to observe and analyze one scoot, constraints were placed on the task so that subjects had the same goal. Physical aspects of the environment that could affect performance include the size and texture of the bed, the absence of covers, and the lighting. In real-world settings, these may be critical features (eg, a firmer surface may cause a different strategy). Further research is needed to determine how meaningful these physical aspects are to achieve a goal. In addition, the subjects were told, "Lie on your back with your arms at your side, legs straight, with your heels touching the foot of the bed." This standardized position represented the starting position. The subjects were asked to lie on their backs after they scooted. Realistically, individuals use a variety of starting and ending positions when scooting in bed.

Factors that may influence the variability in MPs include gender, anthropometrics, fatigability, and force differences in the UE, LE, and trunk muscles. These factors need to be explored in future studies. Furore cross-sectional and longitudinal studies of subjects scooting in bed could also determine whether age-related differences are apparent in MPs used to perform this task. Furore study should also be undertaken to determine whether individuals with physical disabilities demonstrate the same MPs when scooting in bed as observed in individuals without physical disabilities.

Any assessment tool intended for use in multiple settings by multiple raters across many types of patients should be examined[15] for reliability under the full range of possible conditions of its use. Future studies should determine the reliability of this classification system when used by other health care professionals, such as nurses and occupational therapists.

Conclusion

The MPs of young adults scooting supine from the foot to the head of the bed were described. A classification system was developed to categorize the range of patterns used in the axial region, UEs, and LEs. The most common MP combination observed included the "sit slide," "bilateral simultaneous hand push," and "double push" MPs. Young adults demonstrated great variability when scooting in bed. This classification system was found to be reliable for determining the MPs in young adults.

(*) Panasonic Matsushita Electric Industrial Co Ltd, 1360 Higashi-Hiroshuma, Okayama-City, Okinawa, Japan.

References

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[12] VanSant AF. Life-span development in functional tasks. Phys Ther. 1990;70:788-798.

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BG Cohen, PT, is Staff Physical Therapist, Department of Physical Therapy, Bacharach Institute for Rehabilitation, 61 W Jimmie Leeds Rd, Pomona, NJ 08240 (USA) ([e-mail]). Address all correspondence to Ms Cohen.

ER Cardillo, PT, is Staff Physical Therapist, Chestnut Hill Hospital, Philadelphia, Pa.

D Lugg, PT, is Staff Physical Therapist, The Reading Hospital and Medical Center, Reading, Pa.

DN Schwartz, PT, is Staff Physical Therapist, John Schwartz Physical Therapy Service, Long Branch, NJ.

J Mount, PhD, PT, is Associate Professor, Department of Physical Therapy, College of Health Professions, Thomas Jefferson University.

AF VanSant, PhD, PT, is Professor, Department of Physical Therapy, College of Allied Health Professions, Temple University, Philadelphia, Pa.

D Cornman-Levy, PT, is Project Director, A Community/Academic Partnership: A Model to Train Interdisciplinary Health Teams for Underserved Populations, Center for Collaborative Research, Thomas Jefferson University.

Ms Cohen, Ms Cardillo, Ms Lugg, and Ms Schwartz completed this study in partial fulfillment of the requirements for the Master of Science degree in physical therapy, Thomas Jefferson University.

This study was approved by the Institutional Review Board at Thomas Jefferson University.

This article was submitted December 30, 1996, and was accepted February 24, 1998.