Age-related differences in movement patterns used by toddlers to rise from a supine position to erect stance.

Rising to a standing position by young children

is an important step toward developing

independence. Descriptions of movement patterns

that children use to rise from a supine position

to a standing position can be found in the literature.[1,2]

This task is assessed in motor development tests.[3,4] We

believe, however, that these descriptions of performance

are incomplete in light of the qualitative movement

analysis capabilities available today.[5] We contend that

these descriptions lack important details about

upper-extremity (UE), axial region (AX), and lower-extremity

(LE) movements. If incomplete descriptions are used as

standards to determine whether a child is, developing

appropriately, we believe that this causes problems.

Because standing remains an important step in the

development of a child, we argue that physical therapists

would benefit from a more detailed description.

Background

When a child's ability to rise to a standing position

independently is first noted, at an average age of 14

months,[6] the body action is characterized by rotation of

the head, shoulder girdle, trunk, and hips in the coronal

or transverse plane.[1,2] According to Schaltenbrand,[2]

around the fifth year of life, this form of rising is

replaced with symmetrical flexion and extension

movements of the head, shoulder girdle, trunk, and hips.

Two patterns of movement used to rise to a standing

position were described originally by McGraw.[1] In one

pattern, the child moves through a quadrupedal

position to erect standing. Younger children tend to roll

from a supine to a prone position before pushing up

to the quadrupedal position. Older children were

described as sitting up from a supine position, then

moving their "shoulders forward as to gain a

quadrupedal position."[1(p90)] In the other independent form of

rising, as the child moves from a supine to a sitting

position, the lower extremities are flexed to "place feet

on the surface"[1(pp91-92] and then the LEs and trunk

extend to a standing position. McGraw's descriptions

characterized body action as a whole, with details of the

action of each body region left undescribed.

Many contemporary tests of infant motor development

reference the earlier studies of McGrawl[1] and Bayley.[6]

These tests continue to use the total body approach to

describe movements.[3,4] In our view, the movement

pattern descriptions included in these tests are incomplete

and typically include limited descriptions of UE and LE

patterns.

Component Approach to Describing Movement Patterns

VanSant and colleagues have been studying the task of

rising from a supine to a standing position in

cross-sectional studies of a wide range of age groups. Applying

a method introduced by Roberton et al,[7] VanSant[8,9]

utilized a component analysis of movement to formulate

a developmental sequence of movement patterns for the

task of rising to a standing position. This method breaks

body action into three regions: UE, AX, and LE. The use

of the component method rather than the total body

approach was an important breakthrough in qualitative

movement analysis because it allows intra-individual and

inter-individual variation in the rate of development

across different body regions.[8] After studying the

variation across body regions for the task of rising to a

standing position, VanSant[9] proposed a developmental

sequence of the movements for each body region, which

has been partially validated in cross-sectional studies of

children and adults.[10]

VanSant[9] first tested the three proposed component

developmental sequences of movement patterns for

rising to a standing position in a study of 120 children.

The children ranged in age from 4 to 7 years. VanSant

found variability among the subjects that appeared to be

age-related. Different modal patterns were found for

each age group. The descriptive categories of the

movement patterns for the three components were

appropriate for describing children's movements, with a few

modifications and qualifiers. In the UE component, two

categories were expanded from previous identified

categories to include the more asymmetrical movements of

the children. An additional AX movement pattern was

defined, "full rotation, abdomen down," which was

observed only in 4-year-old children. A new

developmental step, "jump to squat," was also added to the LE

component. This step was proposed as a developmental

step, as it was observed most frequently in 4-year-olds and

less frequently in the older age groups. The most

common body action found across all age groups of children

was an asymmetrical push of the UEs, with the trunk

forward with some rotation and the LEs demonstrating

an asymmetrical or wide-based squat pattern. In general,

the older children used more symmetrical movement

patterns than the younger children used.[9] The

development sequences of movement patterns for this task

proposed by VanSant[10] are presented in Table 1.

Table 1.

Movement Patterns for the Task of Rising From a Supine Position to

a Standing Position[10]

Upper-extremity categories

1. Push reach to bilateral push

2. Push and reach

3. Symmetrical push

4. Symmetrical reach

5. Push and reach followed by pushing on leg

6. Push and reach to bilateral push followed by pushing on leg

Trunk categories

1. Full rotation, abdomen down

2. Full rotation, abdomen up

3. Partial rotation

4. Forward with rotation

5. Symmetrical

Lower-extremity categories

1. Kneel

2. Jump to squat

3. Half kneel

4. Asymmetrical/wide-based squat

5. Narrow-based squat

VanSant's developmental sequences[10] have yet to be

validated for children younger than 4 years of age. To

further validate the proposed developmental sequence

for this task, this younger age needs to be studied. The

purposes of our study were (1) to determine whether

movement patterns used to describe young children

rising from the floor to a standing position could be used

to describe movements of toddlers, (2) to determine

whether there are age-related differences in the

movement patterns among toddlers, and (3) to determine

whether movement patterns that are proposed to occur

earliest in the developmental sequence[9] predominated

among toddlers (see Appendix).

Method

Subjects

Sixty toddlers between the ages of 15 and 47 months

participated in this study (Tab. 2). The sample was

one of convenience. Subjects were recruited through

various day-care centers and nursery schools in Mercer

County, NJ.

Table 2.

Subject Characteristics

                                  Age (mo)

                    No. of

Age Group (mo)      Subjects      X          SD



15-25               20            20.5       2.9

26-36               19            30.2       2.6

37-47               21            43.5       2.6

Informed parental consent was obtained for each child.

A parent was asked to provide the child's birthdate and

to assure us that the child had no physical disabilities or

medical conditions that would interfere with physical

activity. To be included in the study, each child had to be

able to walk alone for a few steps and rise to a standing

position without assistance.

The toddlers were divided into three age groups,

representing an 11-month span, to allow study of age

differences across the 15- to 47-month period. Group

characteristics are presented in Table 2.

Design of the Study

The study was designed as a cross-sectional survey to

describe age-related differences in motor performance

of this rising task.[8]

Instrumentation

Two VHS video camcorders were used to record the

children's movements. The two cameras were located to

record a side view and a foot view of each subject. One

camera was placed perpendicular to the length of the

mat, and the other camera was placed perpendicular to

the width of the mat. Each camera was approximately 2.1

to 2.4 m (7-8 ft) away from the center of the mat. The

cameras were placed on tripods, and the zoom lens

(zoom power: 1 x) was adjusted to maximize the size of

the child yet provide a full view of the child and the mat

throughout the rising movement. A board in view of

each camera indicated the subject number and trial

number. A VHS videotape player with stop-action

capabilities and a television monitor were used to reduce

the data.

Data Collection Procedures

Children were videotaped at their day-care centers or at

their schools. Each child was accompanied to the data

collection site by a staff member of the facility. The data

collection procedure was explained in a manner

appropriate for the child's age. Any questions asked by the

child were answered. The child was then asked to lie

down, in a supine position, in the middle of the exercise

mat. This was the starting position for each trial. Some

toddlers in the youngest age group were assisted into the

starting position. The child was then asked to stand up as

quickly as possible on the cue "Stand up." Due to the

young age of the subjects, the cue was modified to be

more motivating, as needed. The child was given general

praise after each trial. As in previous studies,[8,9] an

attempt was made to videotape each child for 10

consecutive trials on this task. If the child became upset during

the videotaping, the data collection stopped until the

child was able and ready to continue. The data collection

was discontinued if the child remained upset or did not

want to continue. Any child who completed at least six

trials was included in the study. No data collection

session lasted more than 15 minutes, regardless of the

number of trials completed. Due to the repetitive nature

of the data collection procedure, external motivators

were used as needed. Older children were rewarded with

stickers. In the two younger groups, when the children

appeared to be restless with the task, they were

encouraged to stand up to get a favorite toy (placed across the

room) or to resume a supine position by lying down on

the mat next to the doll.

Data Reduction

The process of data reduction involved viewing the

videotaped performances and classifying the movements

observed in each of the three components (UE, AX, and

LE) into one of the movement pattern categories listed

in Table 1. The movement pattern categories had been

established in a previous study of 4- to 7-year-old

children.[9] The first author did all classifications. The

footview videotape was used to classify data for all

components. The side-view videotape was used for any trials in

which clarification of the movement was needed to

classify the action.

Upper-extremity movements were classified first. The

first trial of each child was reviewed and classified. The

second trial of each child was then classified. This

procedure continued until the UE movements seen on

the 10th trial (or the last trial of subjects' who completed

fewer than 10 trials) had been classified. This order was

chosen to reduce within-child rater bias.[8] If the trials for

each child were viewed in successive order, there may

have been a bias as to which categorical description was

identified. By viewing trial 1 of subject 1, trial 1 of subject

2, and so on, this bias was reduced (as there were 60

subjects). This procedure was then repeated for the AX

and LE components. If a movement observed in a trial

could not be classified, the movement was described in

writing by the first author. After all trials of all children

were reduced, the written descriptions of the

unclassified trials were reviewed. If the unclassified movement

patterns could not be classified by modifying the existing

categories, the new movements were considered

qualitatively different from existing categories. New categorical

descriptions were formed to encompass these movement

patterns. If a categor-y was modified or new categories

were added, all trials of that component were reclassified

using the new set of categorical descriptions.

Reliability

To ensure interrater reliability, 50 randomly selected

trials were classified by the second author. When there

was 90% or better agreement between the two authors,

the categories were considered to be reliable. Interrater

reliability was determined using a Kappa statistic[11] for

these 50 randomly selected trials. The percentages of

agreement between the authors and the Kappa statistics

are presented in Table 3.

Table 3.

Percentages of Agreement and Kappa Statistics

Movement

Pattern            Kappa          Interrater    Intrarater

Component          Reliability    Agreement     Agreement



Upper extremity    .84            94%           96%

Axial region       .90            90%           86%

Lower extremity    .93            96%           96%

Data Analysis

The existing movement pattern descriptions were

considered accurate if pattern descriptions were not

modified, and they were considered comprehensive if new

patterns were not added. If additional movement

categories were identified, a suggested reordering of the

developmental sequence for that component was made

by both authors.

To determine whether there were age-related

differences in performance among the three groups of

children, the movement patterns for each component for

each age group and the percentage of occurrence of

each pattern within each age group were compared.

In each age group, the percentage of occurrence of each

movement pattern was calculated by dividing the

incidence of the movement pattern by the total number of

trials for that group. The percentage of occurrence

of each movement pattern with respect to age was

presented in graphic form for each of the three

components.

To determine whether toddlers displayed movement

patterns that have been proposed to occur earliest in

development, the modal movement pattern for each

component was determined for each age group and the

order in which the movement patterns predominated

was determined. This order was compared with

VanSant's original hypothesis as to the order of movement

patterns.[10] (Movement patterns are listed in

developmental order in Tab. 1.)

Results

Movement Pattern Categories

The first question we addressed was whether the

movement patterns used to describe young children's

movements (ages 4-7 years) were appropriate for toddlers'

movements. The UE movements of toddlers in the rising

task were accurately described by movement patterns

used to describe 4- to 7-year-old children's movements.

Changes were necessary, however, in the written

description of the partial rotation movement of the AX

component. The description was revised to reflect the greater

degree of trunk rotation observed in this sample of

younger children. The original and revised descriptions

of categories are presented in Table 4.

Table 4.

Modified Axial Region Category: Partial Rotation

Previous Description              Modified Description



Flexion and rotation bring the    Flexion and rotation bring the

  body to a side-facing             body to a side-facing position

  position with the shoulders       or beyond with the shoulders

  remaining above the level         remaining above the level of

  of the pelvis. The back           the pelvis. The back extends

  extends up to the vertical,       up to the vertical, with or

  with or without                   without accompanying

  accompanying rotation.            rotation.

The LE categories were accurate but not comprehensive

for the movements of these toddlers. We created two

new LE categories to describe the distinct movement

patterns observed in this sample.

One pattern was termed "pike." This movement was

characterized by the position of the LEs with respect to

the trunk during the process of rising. The children

demonstrating this action assumed a position in which

the knees were relatively extended as the hips assumed

an acute angle of flexion (Fig. 1). The following is the

description of this LE movement:

The LEs are flexed toward the trunk and may be rotated to

one side with both knees or a knee and foot in contact with

the ground. Both feet then contact the support surface. The

LEs are extended to a pike position. Slight flexion of the

LEs is then followed by full extension during the rise.

[FIGURE 1, ILLUSTRATION OMITTED]

The other new LE category, termed "pike-jump to

squat," differed from the "pike" category in that the

initial base of support described by the pike position is

made smaller by a jumping action, which brings the LEs

toward the hands. Standing is achieved then by

extending the LEs from a squat. In the "pike" category,

standing is achieved by slight flexion of the LEs, followed

by full extension during the rise (Fig. 2). The following

is a description of the "pike-jump to squat" category:

The LEs are flexed toward the trunk, with both knees

contacting the support surface. The feet are then placed in

contact with the support surface while the LEs remain

flexed. Next, the LEs are extended to the pike position.

Both feet are then lifted simultaneously off the support

surface. The feet land back on the support surface in closer

proximity to the hands, with the hips and knees flexing to a

squat position. The LEs are then extended during the rise.

[FIGURE 2, ILLUSTRATION OMITTED]

Age-Related Differences in Upper-Extremity, Axial Region, and

Lower-Extremity Movement Patterns

Upper-extremity component. The most common UE

category for all three age groups was "push and reach to

bilateral push" (Tab. 5). Push and reach was observed

more frequently in the two older groups (ages 26-36

and 37-47 months) as compared with the youngest

group (ages 15-25 months). A small percentage of

children in the two older groups demonstrated the UE

categories "push and reach to bilateral push followed by

pushing on leg" and push and reach followed by

pushing on leg" (Fig. 3), which involve an initial push

followed by a thigh push.

Table 5.

Frequency of Occurrence of Each Movement Pattern for Each Age

Group as a Percentage of Trials in Which They Occurred (Number of

Trials in Each Age Group Shown in Parentheses)

                             Age Groups (mos)

Movement                    15-25        26-36        37-47

Categories                  (n=186)      (n=168)      (n=197)



Upper extremity

  Push and reach to

    bilateral push          92.47         58.58       69.70

  Push and reach             4.30         17.16       21.72

  Symmetrical push           0.00          0.00        0.00

  Symmetrical reach          0.00          0.00        0.00

  Asymmetrical push

    followed by

    pushing on leg           0.00          5.33        3.54

  Push and reach to

    bilateral push

    followed by

    pushing on leg           3.23         11.83        6.57



Axial region

  Full rotation,

    abdomen down            43.55         36.69        4.55

  Full rotation,

    abdomen up              51.08         30.18       55.05

  Partial rotation           5.38         26.63       36.36

  Forward with

    rotation                 0.00          5.92        4.04

  Symmetrical                0.00          0.00        0.00



Lower extremity

  Kneel                     17.74         32.14       20.20

  Jump to squat              0.54          2.38       12.12

  Half kneel                 8.06         23.81       42.93

  Asymmetrical/wide-based

    squat                    0.00         12.50        7.07

  Narrow-based

    squat                    0.00          0.00        0.00

  Pike                      65.59         18.45        9.09

  Pike-jump to squat         8.06         10.71        8.08

[FIGURE 3, GRAPH OMITTED]

Axial region component. The two most common AX

patterns for the two youngest groups (ages 15-25 and

26-36 months) were "full rotation, abdomen up" and

"full rotation, abdomen down." In the oldest group (ages

37-47 months), "full rotation, abdomen up" was the

most prevalent pattern (Fig. 4). Twenty-five percent to

35% of the toddlers in the two oldest groups used the

"partial rotation" pattern. A smaller number of children

in these older groups demonstrated the "forward with

rotation" pattern.

[FIGURE 4, GRAPH OMITTED]

Lower-extremity component. For the LE component,

each age group had a different modal movement

pattern. The newly defined movement pattern, "pike"

(Fig. 1), was the most prevalent pattern in the youngest

group. The "kneel" pattern was most common in the

middle age group. The "half kneel" pattern was most

common in the oldest group. The LE patterns of "pike"

and "pike-jump to squat" were seen in a small percentage

of trials across the three groups. The

"asymmetrical/wide-based squat" pattern was noted in a few trials in the

two older groups. Figure 5 presents the incidence of LE

movement patterns across the three age groups.

[FIGURE 5, GRAPH OMITTED]

Discussion

The UE movement categories developed to describe

young children's and adults' body action in rising to

stand were found to provide accurate and

comprehensive descriptions of toddlers' movements. With the

exception of the "partial rotation" category, the AX

component patterns were also accurate and

comprehensive. New categories were formed to describe LE

movement patterns that were more common among toddlers.

Upper-Extremity Movement Patterns

Toddlers displayed two UE movement patterns, "push

and reach to bilateral push followed by pushing on leg"

and "push and reach followed by pushing on leg," which

were previously identified only in studies of middle-aged

and older adults.[12] These patterns had been predicted by

VanSant[12] to predominate much later in the human life

span (ie, in persons in their 30s, 40s, and 50s and

increasing in incidence with age). Perhaps older adults

and toddlers share a common problem (ie, insufficient

force or strength) that results in the appearance of these

patterns among the two groups. We propose that the two

groups demonstrate the same UE strategy, when

insufficient force is generated in the extensor muscles of the

trunk and LEs.

We suggest that LE- and trunk-force production is a

control variable for this task. Heriza defined a control

variable as one "that shifts the movement from one form

to another."[5(p125)] An individual may change from the

"push and reach to bilateral push" pattern to the "push

and reach to bilateral push by pushing on leg" pattern if

a critical level of quadriceps femoris muscle, hip, or back

extensor force is not produced.

The fact that the two thigh push categories were seen in

toddlers suggests that these categories are not the last

movement patterns to appear in the UE life-span

developmental sequence for this task.[12] This finding raises the

question of whether the categories of "push and reach to

bilateral push followed by pushing on leg" and "push

and reach followed by pushing on leg" should be early

steps in the UE developmental sequence.

We propose reordering the UE movement patterns

based on the varying incidence of UE patterns we found

(Tab. 6). "Push and reach to bilateral push followed by

pushing on leg" is suggested as the earliest category to

predominate, followed by "push and reach to bilateral

push." "Push and reach followed by pushing on leg"

would be the next category predominating, just prior to

"push and reach." The remaining UE categories would

then predominate in the order previously suggested.[10]

Table 6.

Proposed Reordering of Upper-Extremity Categories

New                                                  Previous

Step Category                                        Stop



1    Push and reach to bilateral push followed by    6

       pushing on leg

2    Push and reach to bilateral push                1

3    Asymmetrical push followed by pushing on leg    5

4    Push and reach                                  2

5    Symmetrical push                                3

6    Symmetrical reach                               4

Axial Region Movement Patterns

Because toddlers displayed a greater degree of axial

rotation in the transverse plane than reported for older

subjects,[8,9.12] the "partial rotation" category was modified

to reflect this finding. In the previous description of this

category,[9] the trunk reached a side-facing position (90 [degrees]

of rotation) just prior to the LE extension phase. In the

younger toddlers studied, however, the degree of trunk

rotation was 180 degrees just prior to the LE extension

phase.

The greater degree of axial rotation with respect to the

vertical axis seen in the trials of younger toddlers

appeared to be a variation of the existing "partial

rotation" category. Our decision not to create a new

movement category to represent variations in aspects of

a movement unrelated to the decision rules used to

discriminate is consistent with the decision made in a

previous study of young children.[9] In that study, the

"forward with rotation" category was modified to reflect

the trunk movements of children that differed subtly

from those of adults. Future studies of very young

children could explore possible separation of these

movement categories.

Lower-Extremity Movement Patterns

The decision to define new LE movement patterns was

based on our belief that the patterns were substantially

different from existing LE patterns. In a previous study,[9]

movement categories were broadened to include new

movements that were proposed to be variations of

existing categories. In our study, however, this was not

possible without changing the general intent of the

existing movement categories.

The characteristic feature of both the "pike" and

"pike-jump to squat" categories is the acute angle that the hips

form in relation to the trunk just prior to the rising

phase. When we initially described the "pike" category in

this study, we identified two ways to assume the pike

position. The "pike" category, as it currently is described,

allows a child to move the LEs in a number of different

ways prior to extending the LEs to a pike position. In the

majority of trials, children flexed their LEs toward the

trunk while rotating them and then moved them to a

position of flexion with both feet in contact with the

ground. Then the LEs extended symmetrically to a pike

position. In a smaller number of trials, the LEs were

initially rotated to one side and flexed toward the trunk.

One LE was immediately placed in contact with the

support surface. The LEs then extended asynchronously

to place the opposite foot in contact with the support

surface. This asynchronous LE extension also resulted in

the assumption of a pike position. Although these two

ways of assuming the pike position may be viewed as two

distinct categories in the future, we have chosen not to

separate them at this time because of the low incidence

of trials in which the pike position was assumed through

the asynchronous method. These seemingly different

ways of coming to a pike position need to be more

thoroughly studied among a larger sample of young

children before additional movement categories are

formed.

After we identified the new movement pattern

categories, we proposed a new developmental sequence for the

LE movement patterns. We determined the order of the

categories by examining the relationship of each LE

movement pattern with age. We placed the "pike"

category first in the sequence because it predominated in the

youngest group and declined sharply in incidence in the

two older groups. The developmental position of

the "pike-jump to squat" category is more problematic

because it appeared in a small percentage of trials for all

age groups. The "pike-jump to squat" movement pattern

may exemplify, the LE sequence of toddlers who had

mastered the "pike" movement pattern but were not

ready to move to the next developmental step, "kneel." If

the "pike-jump to squat" pattern is recognized as an

advanced modification of the "pike" pattern, it follows

that the "pike-jump to squat" pattern would be seen after

the "pike" pattern in the LE sequence. The previously

identified LE movement pattern categories would follow

the "pike-jump to squat" pattern in the order previously

predicted[10] of "kneel," "jump to squat," "half kneel,"

"asymmetrical/wide-based squat," and "narrow-based

squat" (Tab. 7).

Table 7.

Proposed Reordering of Lower-Extremity Categories

New                                      Previous

Step    Category                         Step



1       Pike

2       Pike-jump to squat               1

3       Kneel                            2

4       Jump to squat                    3

5       Half kneel                       4

6       Asymmetrical/wide-based squat    5

7       Narrow-based squat               6

Movement Patterns as Developmental Steps

The most common UE movement pattern in toddlers

aged 15 to 47 months was a "push and reach to bilateral

push" pattern. This movement pattern was noted most

frequently in the youngest group, and its frequency

declined slightly in the two older groups. This was the

earliest pattern predicted to occur in the UE

developmental sequence.[9] The data gathered in our study

support this prediction of "push and reach to bilateral

push" as an early-occurring pattern in life-span

development.

In the AX component, the two most common movement

patterns were "full rotation, abdomen down" and "full

rotation, abdomen up." These movement patterns

represent the first and second steps, respectively, in the

developmental sequence for the AX component for this

task. The "full rotation, abdomen down" pattern was

noted most frequently in the youngest group (refer to

Tab. 5 for percentages of each movement pattern across

each age group). The frequency of the pattern declined

slightly in the middle age group and dropped sharply in

the oldest group. The "full rotation, abdomen up"

pattern was also common in the youngest group. This

pattern declined slightly in the middle age group and

was again common in the older group. These findings

support the hypothesis[9] that toddlers would demonstrate

an increased frequency of the movement patterns

predicted to occur earliest in the developmental sequence.

In the LE component, the first predicted step[10] of the

sequence, "kneel," was seen in each of the three age

groups. It was most prevalent in the middle age group, as

noted in 30% of the trials in this group. The "jump to

squat" pattern was noted in a small percentage of the

children across all age groups, gradually increasing in

the oldest group. The data gathered, however, do not

support or negate the position of these patterns in the

developmental sequence. The "half kneel" pattern

showed a gradual increase over the three age groups to

a high of 42.93% of the trials in the oldest group. The

most common LE pattern, however, was the newly

described category "pike." A similar movement pattern

had been observed in a study of 4- to 7-year-old children,

but a descriptive category was not formed due to the

small incidence.[13] The predominance of this new

pattern led to a proposed reordering of the LE categories

(Tab. 7). There was a tendency in the two older groups

of toddlers to use patterns that predominate in the older

children, especially in the AX and LE components.

These results also corroborate the findings of previous

studies of 4- to 7-year-old children[9] in which movement

patterns proposed as early steps were more common

among young children and movement patterns

proposed as later steps were more common among older

children. The results of our study of toddlers help to

support the hypothesis that developmental sequences

for this task can describe movement patterns over the

life span.

Clinical Relevance and Conclusions

Heriza has suggested that although the use of

developmental tests that mark developmental milestones may be

useful in some circumstances, there is a need to develop

evaluation tools that look at the "process of movement

change."[14(p233)] Developmental milestones do not

typically portray the movement patterns used to accomplish

a task. The process of movement change is more likely to

be detected by using a component analysis.

The sensitivity of some developmental tests[3,4] currently

in use may not be adequate to evaluate the process of

change. The criteria in these tests[3,4] do not fully describe

body action, nor do they address variability in action

across body components. The test criteria imply that the

variability of children's movement patterns is not

important. Our study indicates that toddlers' movement

patterns in the rising task can vary greatly across body

regions. We contend that when using test criteria that

incompletely describe children's movement patterns in a

particular task, reliability of scores is jeopardized. The

categorical descriptions of component movement

patterns in the rising task have shown promising intertester

reliability.[8] More complete descriptions of movement

patterns should increase reliability and bring us closer to

documenting the process of movement pattern change.

The component method of studying movement patterns

is easy to apply in the clinic. The method is relatively

inexpensive, and the technical equipment necessary (ie,

a camcorder and a television monitor) are readily

available in many facilities. In a short period of time, physical

therapists could familiarize themselves with the

categories of movement for this task of rising to a standing

position. This method would greatly increase

information on movement pattern performance available to

physical therapists.[12] To date, however, reports of how

this method has been applied to clinical practice and

patient management have not appeared in the

literature.

References

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York, NY. Hafner Press; 1945.

[2] Schaltenbrand G. The development of human motility and motor

disturbances. Archives of Neurology and Psychiatry. 1927;18:720-730.

[3] Rodgers SJ, D'Eugenio DB. Developmental Programming for Infants and

Young Children: Assessment and Application, Volume 5. Schafer DS,

Morersch MS, eds. Ann Arbor, Mich: The University of Michigan Press;

1981.

[4] Folio MR, Fewell RR. Peabody Developmental Motor Scales and Activity

Cards Manual. Allen, Tex: DLM Teaching Resources; 1983.

[5] Heriza CB. Motor development: traditional and contemporary

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Problems: Proceedings of the II Step Conference. Alexandria, Va: Foundation

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[6] Bayley N. Development of Motor Abilities During the First Three Years.

Millwood, NY: Kraus Reprint, Div of The Kraus Organization Ltd; 1935.

[7] Roberton MA, Williams K, Langendorfer S. Pre-longitudinal

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[8] VanSant AF. Rising from a supine position to erect stance:

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[9] VanSant AF. Age differences in movement patterns used by children

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[10] VanSant AF. Life-span motor development. In: Lister MJ, ed.

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1991:77-84.

[11] Cohen J. Weighted Kappa: nominal scale agreement with provision

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[13] VanSant AF. Developmental Sequences for Righting From Supine to Erect

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[14] Heriza CB. Implications of a dynamical systems approach to

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