Movement patterns of adolescents rising from a bed.

Key Words: Functional training and activities; Kinesiology/biomechanics, general; Movement, Pediatrics development

Physical therapists frequently evaluate their patients' ability to get out of bed, a necessary component of the activities of daily living. Clinicians are often interested in not only whether their patients can perform the activity without assistance but also in the movement patterns (MPs) used for getting out of bed.

Sarnacki[1] described the MPs that young adults use to rise from bed and suggested that these patterns vary with age. She described categories of MPs to characterize the MPs observed in each of four body regions: each upper extremity, the axial (AX) region, and the lower extremities (LEs) (Appendix). Whether these MPs vary with age has not been verified.

The purposes of our research were (1) to determine whether descriptions of the MPs used by young adults when rising from a supine position on a bed (Appendix) are comprehensive descriptions of the movements used by adolescents, (2) to determine the most common form of rising used by adolescents, and (3) to determine whether the most common MPs for each body region vary with age. if the patterns used to rise from bed are age related, clinicians treating adolescents could benefit from knowledge of MPs specific to this age group. This knowledge would allow therapists to identify abnormal MPs and teach this functional skill with regard for age-appropriate MPs.

Background

Several researchers[2-4] have documented quantitative changes in motor abilities that accompany growth during the second decade of life. These changes were described as increases in broad-jumping or throwing distances, running speed, or the number of push-ups completed. Few researchers have examined qualitative age-related or developmental changes in MPs used to perform tasks during adolescence. in the late seventies, Roberton and colleagues described MPs of adolescents within the tasks of throwing[5,6] and hopping.[7,8] The MPs used to perform these two activities were reported to change with age during adolescence.

Descriptions of getting out of bed typically suggest a rather specific approach. Carr and Shepherd,[9] in their text on motor relearning following stroke, describe how "most people" and "the elderly" get out of bed. Therapists are instructed to teach patients to come to a sitting position from the side-lying position and correct their tendency to pull on the edge of the bed. Bobath[10] discussed how a caregiver can assist a patient in rising from a supine to a standing position. No description of the "normal" MPs used to get out of bed was provided, although the change of abnormal patterns of movement to normal patterns of movement was a stated treatment goal. As getting out of bed is a task taught by clinicians, clarification of the "normal" MPs used for getting out of bed is important. In this study, the MPs used by adolescents to get out of bed were identified. In addition, intraindividual and interindividual patterns of variability and age-related MP differences were examined.

Method

Subjects

Sixty nondisabled adolescents participated in this study. Subjects were recruited from schools and church groups in the Richmond, Va, metropolitan area. individuals were excluded from the study if they reported any condition that could potentially interfere with their ability to get out of bed, such as an acute or chronic orthopedic or neurological disorder. Informed consent was obtained from the subjects' parents or guardians prior to data collection and from each subject at the time of data collection. The sample was one of convenience. Subjects were recruited until there were 20 subjects in each of three age groups: 11 years, 14 years, and 17 years. The mean age and number of male and female subjects in each group are reported in

Table 1. Mean and Standard Deviation for Age and Number of Male and female
Subjects in Each Age Group
Age Group   Age                       Gender
(Y)         X [bar]       SD          Male      Female
11          11 y 3 mo     2.6 mo      10        10
14          14 y 6 mo     3.4 mo      11         9
17          17 y 6 mo     3.0 mo       9        11

Data Collection

Equipment. A video camera,(*) connected to a power supply and a videocassette player/recorder([dagger]) (VCR), and a video camcorder([double dagger]) were used to record each subject's movements while getting out of bed. The cameras were mounted on tripods. Each camera was equipped with an automatic focus, a power zoom lens, and an electronic view finder. The bed was a standard twin-sized bed measuring approximately 1.88 m long, 0.96 m wide, and 0.51 m high. A sheet was used to cover the mattress, and a pillow was provided at the head of the bed.

Layout of data-collection site.

One camera was positioned facing one side of the bed, with the optical axis of the lens perpendicular to the length of the bed. The other camera was positioned facing the foot of the bed with the optical axis of the lens perpendicular to the width of the bed. The side-view camera was located approximately 7.2 m from the center of the bed, and the foot-view camera was 6.2 m away. The distance from the floor to the center of the camera lens was approximately 0.87 m for the side-view camera and 0.93 m for the foot-view camera. A board with two sets of numbers was placed within view of both cameras and was used to identify subject and trial numbers.

Procedures. One investigator (JOM) and assistants collected the data. The purposes and procedures of the study were first explained to the subjects. Each subject was asked to remove his or her shoes and socks and to lie supine in the center of the bed with the arms beside the body. Two commands, "ready" and "go," were given. On the command "ready," video recording was started, and on the command "go," the subject rose as rapidly as possible and stood until asked to lie back down. To prevent the subjects from thinking about the form of their movements,11 they were asked to rise quickly. All subjects turned to their left side while rising. The direction of rising was determined by environmental constraints of the first videotaping site. Ten consecutive trials were recorded. Intervals between trials were paced by the subjects, with generally only a few seconds between trials.

Data Reduction

Training for data reduction. Prior to classifying the adolescents' MPs, 50 trials from Sarnacki's[1] films of young adults were randomly selected and independently classified for each body region by each investigator (JOM and AFV). If less than 85% agreement was obtained, discrepancies were identified, and any misinterpretations of the MP descriptions were corrected based on comparison with Sarnacki's initial classifications. Additional sets of 50 randomly selected trials were classified by both raters until at least 85% agreement was reached for each body region. During the training process, the percentages of agreement between raters were 88%, 88%, 94%, and 90% for the "far upper extremity" (FUE), "near upper extremity" (NUE), AX, and LE regions, respectively.

Movement pattern classification

Videotapes were analyzed using a television monitor and a VCR with stop-action and slow-motion playback capabilities. The first author (JOM) used Sarnacki's MP descriptions (Appendix)[1] to classify the movements of each body region. Because Sarnacki's subjects had risen by turning toward their right side, we eliminated references to the right and left sides of the body from the MP descriptions used in our considerations. Instead, we substituted the terms "near upper extremity" for the arm initially closest to the side of the bed from which the subject rose and "far upper extremity" for the other arm.

The first trial of each subject was viewed, and the NUE MP was categorized. The second trial of each subject was then viewed and so forth until movements of the NUE on all 10 trials had been classified. Movement patterns that could not be classified were described by the investigator (JOM) in writing. This procedure was then repeated for each of the other three body regions: the FUE, the AX region, and the LEs.

Reliability. After data reduction was completed, interrater reliability of the classification process was examined for each body region. Data from 60 randomly selected trials were classified by the second author (AFV) and compared with the first author's categorizations. If less than 85% agreement was obtained, discrepancies were identified, and the descriptive categories were clarified. If necessary, "decision rules" were written by the investigators to assist with MP classification. The first author then repeated the classification process within that body region, another set of 60 trials was randomly selected, and the process was repeated. When at least 85% agreement was obtained, a Kappa statistic[12] was calculated for that body region as an estimate of interrater reliability.

The percentages of agreement achieved between raters using the adolescents' videotapes are reported in Table 2 along with the Kappa statistics used to examine interrater reliability. The values of Kappa ranged from .76 to .91, indicating acceptable levels of rating consistency.

Table 2. Interrater Percentages of
Agreement and Kappa Statistics for Each
Component of Body Action
                 Percentage of
Component        Agreement         Kappa
Far upper
  extremity      95.0              .91
Near upper
  extremity      85.0              .76
Axial region     90.0              .89
Lower
  extremities    86.5              .82

Data Analysis

Comprehensiveness of existing movement pattern descriptions.

The comprehensive nature of the MP descriptions was analyzed by determining how many of the subjects' movements could not be categorized and had to be described in writing. If Sarnacki's categories[1] had to be revised or if new descriptive categories had to be formed to portray adolescents' rising movements, then the MP descriptions were not considered to be comprehensive of adolescents' movements.

A new MP was identified for the NUE that had not been described by Sarnacki.[1] This new pattern was termed "Lift and Reach" and is described as follows:

The leading upper extremity is lifted

off the bed without pushing. The extremity

may be used to reach forward

or as a balance assist. The remaining NUE MP descriptions were used without modification to characterize the subjects' rising movements. No new patterns were identified for the FUE, AX, or LE regions.

Although no new patterns were observed in the AX region, three of the four original descriptions were rewritten to better characterize the MPs and to make them more generalizable. These revised descriptions are presented in Table 3. After the AX pattern descriptions were revised, data from this study were reclassified for the AX region. Interrater reliability was examined for this component using 100 trials randomly selected from three data sets: our adolescent subjects, young adults,[1] and middle-aged adults.[13] This was done to ensure the reliability of the descriptions when used across a wider age range. We attained 88% agreement, and the value of Kappa was .76. No modifications were required for the NUE, FUE, or LE pattern. [TABULAR DATA 3 OMITTED]

Most common form of rising. The MPs demonstrated in each of the four body regions were combined to form a "body action profile." Profiles were constructed for all subjects on each trial. The number of different rising profiles exhibited by the subjects was determined across all trials. The incidence of each profile was also determined within and across the three age groups. The most commonly observed profiles were identified for the entire group of subjects and for each age group.

Age-related movement pattern differences. For each body region, the incidence of each MP was determined for each age group. To examine age-group differences, the incidence was expressed as a percentage of occurrence across the trials of an age group and was graphed with respect to age for each body region.

Results

Most Common Form of Rising

Tremendous variability was observed within and across subjects. Eighty-nine different combinations of FUE, NUE, AX, and LE MPs, or body action profiles, were observed in this sample of adolescents. Sixty-seven of these combinations were observed in the 11-year-old group, compared with 40 combinations in the 14-year-old subjects and 44 combinations in the 17-year-old group. No subjects demonstrated the same combination of MPs across their 10 trials. One body action profile was among the most common profiles of each age group. That rising action involved a doublepush pattern with the FUE, a grasp and push pattern with the NUE, a come-to-sit pattern in the AX region, and asynchronous lifting with leg extension with the LEs. This pattern is illustrated in Figure 1.

The three body action profiles observed most frequently among the 11-year-old subjects were each seen in only approximately 6% of that group's trials. Thus, more than 80% of the 11-year-old group's trials were dispersed among 64 other combinations of MPs. The most common patterns differed from one another only in NUE or AX action and are illustrated in Figures 1, 2, and 3. For subjects 14 years of age, two common MP combinations were each seen in approximately 12% of the trials. These patterns differed only in LE action and are illustrated in Figures 1 and 4. The profile illustrated in Figure 1, which was common across both the 11- and 14-year-old age groups was also the single most common form of rising among the 17-year-old subjects. This combination of MPs was observed during approximately 15% of their trials.

Age-related Movement Pattern Differences

The incidence (frequency of occurrence) of each MP for each component is listed in Table 4. In Figures 5 through 8, these incidences are graphed with respect to age for each body region.

Table 4. Incidence (Frequency of
Occurrence) of Each Movement Pattern
in Each Age Group
                                  Age Group (y)
Movement Pattern              11        14        17
Far upper extremity
  Lateral lift and push       1.5       0.0       0.0
  Push                       16.5      16.5      20.0
  Double push                72.0      83.0      63.5
  Lift and push               8.0       0.5      13.0
  Lift and reach              2.0       0.0       3.5
Near upper extremity
  Lateral lift and push      25.0       9.5      10.5
  Grasp and push             36.5      48.5      42.0
  Push                       38.0      42.0      47.0
  Lift and reach              0.5       0.0       0.5
Axial region
  Pelvis leads                5.0       0.0       4.5
  Lateral roll               34.5      10.0       1.5
  Roll off                   17.5      14.5      24.0
  Come to sit                43.0      75.5      70.0
Lower extremities
  Step off                   10.5      32.5      17.0
  Asynchronous lifting
    with leg extension       44.5      28.0      47.5
  Asynchronous lift          32.5      26.0      28.5
  Synchronous                12.5      13.5       7.0

Far upper extremity. The MP that predominated in all age groups was the double-push pattern. This pattern demonstrated a peak (ie, highest) incidence in the 14-year-old subjects when compared with the younger and older age groups. Push was the second most common pattern of each age group. The other three patterns were seen so infrequently that age-related trends in their incidence were not apparent.

Near upper extremity. The predominant MP varied with age in the NUE. In 11- and 17-year-old subjects, the push pattern was slightly more common than the grasp and push pattern, which predominated in the 14-year-old group. These two patterns accounted for approximately 75% to 90% of the trials of these subjects. The lateral lift and push pattern was more commonly used by the youngest subjects. The lift and reach pattern, a newly identified pattern, was seen infrequently and not observed in the 14-year-old subjects.

Axial region. The come-to-sit pattern was predominant across all age groups for the AX region. The lateral roll pattern was relatively common in the 11-year-old subjects and less common in the older age groups. The roll-off pattern was observed with higher frequency in the oldest age group when compared with the younger subjects. The pattern pelvis leads was uncommon at all ages studied.

Lower extremities. Asynchronous lifting with leg extension was the predominant pattern in both the 11- and 17-year-old subjects. Step off, which was the least common pattern of the 11-year-old subjects, predominated in the 14-year-old group. The other two LE patterns varied little with age. The synchronous pattern was relatively uncommon, being seen in only approximately 5% to 15% of the trials of all age groups. The asynchronous lift pattern was observed more commonly in approximately 30% of the trials of all age groups.

Discussion

Movement Pattern Categories

With the exception of the new pattern identified in the NUE, the MPs described by Sarnacki[1] were found to be comprehensive of the movements demonstrated by the adolescents. Movement patterns observed in adults performing the task of getting out of bed, therefore, appear to be representative of most MPs observed in teenaged individuals. Although developmentally earlier- or later-appearing MPs may not be observed when a sample of young adults is used to identify the MPs for a task,[14] Sarnacki's study of young adults[1] proved a useful first step prior to studying adolescents.

The new NUE pattern identified in this study was sufficiently distinct from other patterns to warrant formation of a separate descriptive category. This pattern, however, was observed in only two subjects. Because of its low incidence in our study and its absence among young adults,[1] the question of whether this pattern varies with age cannot be answered at this time.

We believe the revisions of the AX region categories better emphasize discriminating features among AX MPs. The higher incidence of the lateral roll in our adolescents as compared with young adults (5% of their trials)[1] seems to have made it easier to distinguish key features among the lateral roll, roll-off, and come-to-sit patterns. The lower Kappa statistic, however, suggests that our revised categorical descriptions may require further refinement. We would suggest continued use of the revised descriptions among varied age groups before a final assessment of their validity is made.

Most Common Form of Rising

There was a tremendous amount of intraindividual and interindividual variability in the body action profiles used by these adolescent subjects when getting out of bed. This variability was evidenced by the large number of different profiles observed, by the small incidences of the most common profiles, and by the fact that no subject demonstrated the same profile across all 10 trials. Adolescents clearly have a number of different MP combinations available when getting out of bed.

Biomechanical constraints, however, may restrict the number of possible MP combinations.[1] For example, for a subject to simultaneously demonstrate a lateral roll pattern in the AX region and a lift and reach pattern in the NUE would be unlikely. Once in a side-lying position, for the subject to move toward sitting without pushing or grasping on the bed with the NUE would be difficult.

The greatest variability was observed in the 11-year-olds and was evidenced in three ways. First, the 11-year-olds demonstrated more MP combinations than did the 14- or 17-year-olds. They also demonstrated three different body profiles with relatively equal frequency as their most common performances, compared with two profiles in the 14-year-olds and one profile in the 17-year-olds. Finally, the most common profiles observed among 11-year-olds were observed less frequently than the most common profiles of the 14- or 17-year-old group. This greater variability among younger subjects may indicate that younger adolescents are more likely to be in a process of developmental change than older adolescents.

One of the three body action profiles demonstrated commonly by the 11-year-olds was also one of the two most common combinations among the 14-year-olds and the most common combination demonstrated by the 17-year-olds. This finding suggests that the age intervals chosen for this study may have been too small. Age differences in the most common body action profiles and individual MPs might have been more apparent if larger age intervals, perhaps 4 or 5 years, had been selected.

The most common body action profiles of adolescents (Figs. 1-4) differed from that characteristic of young adults.[1] Young adults most commonly demonstrated a push action with the FUE, a grasp and push pattern with the NUE, roll off in the AX region, and an asynchronous lift with the LEs. The adolescents differed in the FUE, AX, and LE regions. This finding further supports the premise that there are developmental differences in the body action used to get out of bed.

Age-related Movement Pattern Differences

There was little difference among the age groups in the incidence of four of the five FUE patterns. The double-push pattern was by far the predominant pattern of each age group. The peak incidence of this pattern in the 14-year-old subjects when compared with the older and younger age groups was the only notable age-related difference observed in this component.

We compared our results with the incidence Sarnacki[1] reported for each FUE pattern and found differences that cause us to conclude that the MPs of the FUE vary with age. The push pattern was the most common FUE MP in young adults (20-35 years of age), being observed in approximately two thirds of their trials as compared with only 15% to 20% of our adolescent subjects' trials. Similarly, the lateral lift and push pattern was reported to have a higher incidence in the young adult subjects than we observed in our subjects. The trend revealed when comparing the data from this study with the data reported for young adults suggests that the lateral lift and push pattern may be predominant after young adulthood. As a result of this comparison, we suggest that across later childhood, adolescence, and into adulthood, the FUE MPs likely predominate in the following order: first double push, followed by push, and then finally lateral lift and push. Because the lift and push and the lift and reach patterns were seen so infrequently in this study and in Sarnacki's subjects, we are unable to predict developmental trends for these two patterns.

In the NUE, the relatively equal incidence of the grasp and push and the push patterns and their alternating dominance did not enable an unequivocal prediction of the developmental order of these two patterns. The trend toward a reduced incidence of the lateral lift and push pattern in the older age groups suggests that this pattern may be even more common before the age of 11 years. Our small sample size is a major limiting factor. Further study with a larger sample and extension of the age range into later childhood should help verify the order of development of MPs for this body region. Sarnacki,[1] however, found that the grasp and push pattern was predominant in young adults (59%). The push pattern, predominant in our 17-year-old subjects, was relatively uncommon in young adults (18.5%). We therefore hypothesize that the NUE MPs predominate across later childhood (ie, 8-9 years of age[11]), adolescence (ie, 10-19 years of age[15]), and into young adulthood (ie, 20-35 years of age[1]) in the following order: lateral lift and push, push, and grasp and push.

In the AX region, the pelvis-leads pattern demonstrated no clear relationship with age and may not represent a developmental step. The lateral roll pattern was more common in younger subjects than in older adolescents or Sarnacki's young adult subjects,[1] suggesting that this is an early developmental step. The come-to-sit pattern, predominant in adolescents, was reported to have a somewhat lower incidence among young adults 41%). The roll-off pattern demonstrated an increasing frequency with increasing age across adolescence and was predominant in young adults (51%). We therefore propose that the developmental order of patterns across the period of later childhood, adolescence, and into young adulthood is first lateral roll, then come to sit, and then roll off

Our LE data, when compared with the results reported by Sarnacki,[1] also allow us to hypothesize a developmental order for these MPs. In accordance with the age differences in the predominant patterns, we suggest that the order of development would be (1) asynchronous lifting with leg extension, (2) step off, (3) asynchronous lifting with leg extension, and (4) asynchronous lift and synchronous patterns. Asynchronous lift represented the dominant LE action among young adults (33.8%).

Clinical implications

At times, a specific approach to getting out of bed may be appropriate, for example, following an acute back injury or in the later stages of pregnancy. The great MP variability observed within and across individuals getting out of bed, however, suggests that a less specific approach is generally more appropriate. Knowledge of the MPs common for the patient's chronological age may represent a starting point when assessing and teaching this task. Although many possible combinations of MPs or body action profiles exist, the number of identified MPs within each body region is small.

The ability to vary one's movements is another important consideration. Fostering the development of several patterns, or movement strategies, is clearly indicated within this task. Further study is needed to determine whether individuals with physical disabilities demonstrate the same MPs or the same degree of variability when getting out of bed as we observed in individuals without physical disabilities.

Conclusions

With the exception of one new NUE pattern identified in this study, we were able to describe the MPs that adolescents use to rise from bed by using descriptive categories developed in Sarnacki's study of young adult subjects.[1] Although a great deal of variability in MPs should be expected among individuals, there is one combination of MPs that is relatively common across adolescence. Sarnacki's hypothesis that the MPs used to perform this task vary with age has received preliminary validation in this study, and we have proposed a developmental order of MPs for each body region studied. Further study of a larger sample with a broader age range is indicated to further clarify the proposed developmental orders.

Acknowledgments

We wish to thank all the students, parents, facility administrators, and data-collection assistants who participated in this study. We give special thanks to Pam Cox, Steve Green, and Allane Storto for their assistance in the preparation of this manuscript.

References

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