Winnie Yuen Yee Chan,

Christine Chapparo

WinnieYuen Yee Chan, BAppSc(OT)(Hons) is an occupational therapist workingat the Singapore General Hospital. This paper reports on part of herHonour’s Thesis ‘The effects of wrist immobilisation on upper limbfunction in elderly males’, submitted through the School ofOccupational Therapy, The University of Sydney.

ChristineChapparo,MA,DipOT,OTR,FAOTA, is a senior lecturer in the School ofOccupational Therapy, Faculty of Health Sciences, The University ofSydney.

ABSTRACT

Nine normal male subjects, between 60-79 years old participated in a study designed to determine the effect of wrist immobilisation on upper limb occupational performance. An upper limb measurement system using the Motion Analysis System, ExpertvisionTM was developed and this was used to quantify and describe the three dimensional movement of the subjects during performance on the Jebsen Hand Function test. Comparisons of the time, and range of the upper limb movement between the free and immobilised wrist condition were made. Results revealed statistically significant increases in the time taken and the total degree of shoulder motion used, as well as significant decreases in the total elbow motion during the immobilised condition. Results also showed great variation in the effect of wrist immobilisation on upper limb joints. These reinforce the need for occupational therapists to evaluate the upper limb as an entity and to evaluate each client on an individual basis when immobilising the wrist. The upper limb measurement system in this study provides future direction for research methodology that can analyze the effects of orthotic intervention on everyday occupational performance.

INTRODUCTION

Hand splinting plays an important role in the physical rehabilitation of clients with neurological and orthopaedic disorders. One common splint used by occupational therapists to improve hand function is the static wrist hand orthosis. Research evidence supports the use of static wrist hand orthoses to increase wrist stability and diminish pain (Carlson & Trombly, 1983; Kraft & Detels, l972; Linscheid & Beckenbaugh, l976; Malick, 1988; Millender & Nalebuff, 1973; Stern, 1991). When the wrist is stabilised through application of a wrist hand orthosis and pain is reduced, then the function of the hand is assumed to be improved. However, reservations in using splints are also expressed by some authors, on the basis that external mechanical devices, such as the wrist hand orthosis, may interfere with normal hand and upper limb function (Barr & Swan, 1988; Brand, 1985; Carr & Shepherd, 1987; Charness, 1988; Perry, 1975).

Although physiological responses to joint immobilisation are well documented, adequate information concerning the biomechanical effects of wrist immobilisation on the hand is not available. Little has been done to investigate the effect of wrist immobilisation on hand function and compensatory upper limb movement. If these effects can be better defined and identified, occupational therapists may be in a better position to weight the gain and loss of splinting relative to occupational performance and determine if use is justified on a case to case basis. This will enhance the clinical reasoning process of determining the most appropriate candidates for orthotic application.

It is well recognised that the upper limb works as a mechanical linkage unit and that immobilisation of one part has a potential impact on movement patterns of the entire upper limb. Previous research studying the biomechanical effects of wrist immobilisation has been limited to evaluating the effect on function solely on the basis of time (Carlson and Trombly, 1983; Stern 1991). This research offers little information about the altered prehension patterns caused by orthotic application during occupational performance. In an attempt to demonstrate the link between speed and quality of hand function, an upper extremity measurement system was developed in this study using a motion analysis system (ExpertvisionTM). With this system, the three-dimensional movement of the upper extremity during common daily activities was quantified. This provided more information on the impact of wrist immobilisation on upper limb movement, and gave useful information about the normal variability in the upper limb movement during activities of daily living.

REVIEWOF THE LITERATURE

The upper extremity is divided into five functional units: 1) Shoulder girdle 2) Shoulder joint 3) Elbow 4) Radioulnar joint 5) Wrist and hand (Kreighbaum & Barthels, 1985). These functional units work together to promote efficient upper limb function (Barr & Swan, 1988; Lehmkuhl & Smith, 1983). The wrist, being the most distal joint of the upper limb before the hand, is the final determinant of hand location and gives precision to hand placement. It also allows the hand to assume the optimal position for prehension (Perry, 1978).

Although the wrist joint is an important functional unit of the upper extremity, it is also vulnerable to a wide assortment of injuries and diseases. Static wrist hand orthoses are frequently prescribed to rest and to protect structures of the hand, to prevent deformity or to support a painful joint (Barr & Swan, 1988; Malick, 1976; Rossi, 1988). When the wrist is immobilised, its three major functions are compromised. They include providing stability for hand function, augmenting grip strength, and positioning the fingers (Carlson & Trombly, 1983; Millender, & Nalebuff, 1973; Sarrafian, 1975). Not only is hand function potentially affected, but changed motion above or below the wrist may result.

Two studies compared the time taken to complete the Jebsen hand function test (JHFT) in a free and immobilised hand position (Carlson & Trombly, 1983; Stern, 1991). Both studies revealed that a significantly longer time was required for all the subtests in the immobilised condition than in the free hand condition. Quality and change in upper limb movement, however, was not studied.

Although compensatory upper limb movements during wrist immobilisation have not been specifically measured in reported research studies, they have been described. Millender et al. (1973) evaluated the effect of wrist fusion on hand function in sixty clients. Follow up of the clients described uniform patterns of substitution, which involved the elbow and shoulder.

In Carlson et al.’s (1983) study, subjects reported feeling mild fatigue in their shoulder and upper trunk after upper limb performance in the immobilised wrist condition. This indicated an accommodation of these joints to wrist immobilisation. Stern (1991) noted differences in patterns that were used for grasping a spoon during eating when performance of the free and immobilised state of the wrist was compared. The pattern employed by subjects when the wrists were immobilised emphasised movement of the elbow and shoulder rather than wrist and finger.

The concept of the upper limb functioning as an entity, with each segment interdependent on the another found early support by Linscheid and Beckenbaugh (1976) and later Feldon (1988). Linscheid et al proposed that arthrodesis of the wrist places a greater demand on the other parts of the upper limb for positioning the hand. Similarly, Feldon suggested that upper extremity function is not greatly undermined by wrist immobilisation as long as the rest of the upper limb joints have relatively well preserved function and are able to position the hand in space.

Despite the wide range of literature suggesting the presence of compensatory movement on wrist immobilisation, experimental evidence demonstrating the relationship between wrist immobilisation and compensatory movement has not yet been established. There is support, therefore, for investigation of the changes in active range of motion of upper limb joints during occupational performance while in both free and immobilised conditions.

Recent advances in motion analysis techniques have made possible the measurement of body movement in three dimensions using multiple videography. In 1989, The Motion Analysis Corporation designed the Motion Analysis System, ExpertvisionTM to provide clinicians and researchers with a method to determine quantitative measurements of joint movements in place of subjective estimates. To date, this measurement system has been mostly limited to gait analysis of the lower limb in rehabilitation biomechanics (DeLozier, Alexander, & Narayanaswamy, 1991; Moseley, 1992). This may be due to the fact that analysis of the upper limb involves multiple joints and is considered more complicated and time-consuming than lower limb analysis.

This study was conducted on nine elderly male subjects. In elderly people, there are age related changes in joints, bones and muscles which may have additional implications for the effect of joint immobilisation (Linscheid and Beckenbaugh, 1976). Previous studies conducted by Carlson et al. (1983) and Stern (1991) to investigate the effect of wrist immobilisation on hand function employed a younger population. The results provided little insight as to how 60-79 year-old individuals might react to wrist immobilisation. Given that elderly people make up a large percentage of occupational therapy clients that receive orthotic intervention, it was considered important to study the effects of immobilisation on individuals in this age range.

The purpose of this study was therefore, to:

1.develop an upper limb measurement system to quantify the upper limb movement of elderly males during occupational performance,.

2. to determine the effect of wrist immobilisation on upper limb occupational performance in elderly males.

METHODS

Subjects

9 elderly males, ranging in age from 60-78 years, volunteered for and completed the study. They had no known orthopaedic and neurological problems and were right-hand dominant. All participants were retired.

Instrumentation

a. Jebsen hand function test (JHFT) evaluates unilateral hand function which includes a series of seven subtests representing a wide range of occupational performance tasks involving the upper extremity. They are: 1) copying a 24 letter sentence, 2) turning over cards 3) picking up small common objects 4) simulated eating 5) stacking checkers 6) moving large empty cans;

7) moving weighted cans.

The JHFT was chosen because it was reviewed in the literature as being able to fulfil the validity and reliability requirements of a standardised test (Backman, Mackie & Harris, 1971; Fess, 1986). It also emphasised functional task performance, which supports the occupational performance frame of reference underlying this study.

b. The Motion Analysis ExpertisionTM system is a video and computer based motion tracking and analysis system for examining three dimensional (3-D) motion. There are four principal components in this system (Figure 1):

*a video monitor for checking of camera views

*video cameras to detect position of markers and send video signals to video processor

*a Motion Analysis video processor which automatically converts video images into 2-D marker outline positions

*a host computer with ExpertvisionTM 3-D software to generate kinematic and statistical data describing the behaviour of the markers.

Figure1: Four Components of the Motion Analysis System

For this study, 14 reflective markers were attached to the subject and six video cameras were used to record the images from the markers at 60 frames per second.

The ExpertvisionTM was chosen because it was able to transmit video images directly thereby eliminating multiple human operations that are required in photographic analysis. The use of light weight reflective markers in multiple joint evaluation of the upper limb were chosen because they cause minimal encumbrance to movement. In addition, it was also reported by the manufacturer and VanderLinden, Carlson and Hubbard (1992) that the system used is a reliable and accurate system in providing angle measurements when using the reflective markers.

Procedures

1. Set up of the data collection area

To accurately and reliably measure the 3-D upper limb movement during the JHFT, numerous pilot trials were conducted to finalise the protocol of setting up the data collection area so that optimal marker images were obtained. These involved careful investigation of the effects of varying the (1) camera placement (2) marker positions and (3) marker sizes on the marker images obtained. Six final camera positions were chosen. Five cameras were placed from right to left of the subject’s working space. One camera was mounted overhead. Six cameras were used to ensure that every marker remained in view of at least two cameras at any one instant.

The data collection area was calibrated prior to each subject̓s testing by a 3-D calibration structure with known locations. The relationship between 2-D camera image co-ordinates and the known 3-D object space co-ordinates was determined. The calibration structure was then removed and the subject was videotaped in the same object space without altering the camera configuration.

2. Test administration

Each subject completed the JHFT according to the published protocol as described by Jebsen et al (1969). The following exceptions were adopted: 1) Only the right dominant hand was tested. 2) In Test 2 the subjects were requested to turn the cards in a standardised way suit the purpose of motion analysis in this study. 3. Additional criteria for placement of test items were also included to allow valid comparison of movement between and within subjects

Subjects were asked to perform the test twice, once in the free wrist condition and another in the immobilised condition. To control for the effect of practice, 4 subjects started with the free condition while 5 started with the immobilised condition. Before data collection commenced, subjects were given time to practice each test item in the free wrist condition until the performance time levelled off. No practice trials were done in the immobilised condition.

3. Orthotic application

In the immobilised condition, a wrist hand orthosis that holds the wrist at 20° wrist extension was applied to the subjectÌ“s right wrist.Three sizes: small, medium and large sizes were available and the orthosis of best fit was applied.

4. Timing of performance

A light synchroniser was set up so that a light beam was targeted at one of the cameras (camera two). At the command “go!”, the researcher manually activated the light synchroniser and again at the completion of the tests. The ExpertvisionTM was then used as a timing device by determining the number of frames between the appearance of the two light beams on camera two. The value was divided by 60 to obtain the number of seconds in two decimal places.

5. Motion Analysis: movement pattern

14 markers were placed on the subject̓s right anterior thorax and upper limb. Markers sites were carefully chosen during the pilot phase to minimise errors as a result of skin or soft tissue movement. Sites that resulted in coalescing of markers during test performance were also avoided. The finalised marker sites is shown in Table 1.

During the performance of the JHFT, images of the retroreflective markers were recorded by the Motion analysis system at 60 frames per second. Up to 25 seconds of each subtest were videotaped and video signals were fed directly to the video processor for digitising. At the same time, recordings were also made to provide a means of archiving the data as standard video images.

Digitisation of the image of movement during test performance from each camera was performed on line by the Video Processor (VP320) and stored in memory as pixel positions corresponding to the edge of each marker. The digitised data were then transferred to the SUN/sparc 4-110 Colour Graphics Work station Table1: Marker Sites and stored in files on hard disc.

6. Reliability of Test Administration

Consistency of test administration was achieved by involving the same two testers for all subjects. Testers were trained prior to the data collection to reach 100% agreement on both administration and measurement of performance on the JHFT. Intratester agreement of 98.9% was established prior to the beginning of the study by test-retesting of the videotaped performance of five subjects in the pilot trials.

7. Data reduction

To obtain the movement path of each marker, tracking was performed by the computer and was monitored closely by the researchers to minimise digitisation errors. On completion, marker paths were visually inspected and manually edited to free data from contamination by undetected digitisation errors. Problems such as gaps in marker paths were resolved by extrapolation between known locations preceding and following the gap. Data were then smoothed using the two-pass fourth-order Butterworth filter at the frequency of 10 hertz.

Two sets of data were developed from the total data pool.
1) time taken to perform the subtests and
2) proximal joint motion used to complete the subtests.

The motion data was in turn divided into five subsets:
a. trunk rotation, b. trunk side flexion, c. shoulder, d. elbow and e. wrist.

In this study, one data record was equated with the pair of scores (free and immobilised) of one subject for each data set and each subtest. Thus, one subject generated 42 records (6 data set x 7 subtest), yielding a total of 378 records for 9 subjects. Each record was examined for unacceptable quality.

DATAANALYSIS

Means and standard deviations were calculated for all data sets using the SPSS-x packages (SPSSxTM, 1986). One tailed t-test for paired samples was used to determine if there were statistically significant differences in the means of time in the free and immobilised condition. Directional, one tailed t-test was used as prior research studies indicated that the immobilised wrist would take a longer time to complete the tests than that of the free condition (Stern, 1991; Carlson, et al., 1983).

Two analyses were perform using the motion data sets: first, the total degrees of motion for the trunk were computed for each subtest and then comparisons were made between the two conditions. Similar analysis was completed for the shoulder and elbow. The purpose of this analysis was to determine the general trend of the compensatory pattern of the trunk, shoulder and elbow when the wrist was immobilised. Second, the degrees of motion in the proximal parts of the upper limb was also examined individually across each subtest. The purpose of this analysis was to determine whether upper limb performance was more affected by wrist immobilisation in some tasks than others.

Non-parametric Wilcoxon test for related means was used for the motion scores. The non-parametric test was chosen over two-tailed t-test because it does not assume normality of data and is applicable to the small sample size in this study.

RESULTS

Time

Means and standard deviation scores for time of performance in each subtest are included in Table 2. Subjects took a longer time to complete all the subtests in the immobilised condition than in the free condition Setting the significance level at 0.05, a significant increase in time was found for all subtests except test six (Table 2).

Mean time taken to complete the subtests in the free condition appeared to be slower than the normative value for males in similar age groups of past studies (Hackel, et al., 1992; Jebsen, et al., 1969). Criteria of performance in this study was slightly modified to suit the motion analysis purpose. For instance, instead of holding on to the pen in test one before timing begins, as stated in the original Jebsen protocol, subjects were asked to pick up the pen themselves. Likewise, the subjects were asked to pick up the spoon in test four. In test two, subjects were also requested to turn the index card in a standardised way. These modifications could have contributed to the differences in the results between this study and others reported in the literature.

Movementpattern: Total degrees of motion (All tests)

Means and standard deviations of the total degrees of motion of the upper limb joints in the entire JHFT were computed and included in Table 3. Both rotation and side flexion of the trunk, as well as the shoulder showed an increase in the mean degrees of motion in the immobilised condition. The elbow was the only joint that had a reduction in mean score when the wrist was immobilised. Non-parametric Wilcoxon test revealed that only the shoulder and elbow showed significant differences in the overall degree of motion (p<0.05, df=8). The shoulder showed a significant increase and the elbow a significant reduction in motion. This indicates that the shoulder moved significantly more and the elbow significantly less when the wrist was immobilised.

Movementpattern: Degrees of motion (Across each test)

When the two conditions were compared across each subtest performance, it is seen that all tests except Test 1.(writing) and Test 3. (picking up small objects) followed the general trend of the previous analysis: ie increased motion at the trunk and shoulder, with restriction in the elbow (Table 4).

Writing was the only test that showed a reverse pattern where rotation of the trunk and shoulder movement was reduced and elbow motion increased. Test three: picking up small objects, on the other hand, showed an increase in motion for all joints including that of the elbow. In spite of the significant differences of the total degrees of motion in the shoulder and elbow found in the previous analysis, only four out of twenty eight subtests revealed significant differences at the 0.05 level when analysed statistically across each subtest. (Table 5)

Wilcoxon paired tests revealed that side flexion of trunk in placing light cans, shoulder in stacking checkers, elbow in turning over cards and simulated eating showed significant differences in the degree of motion when compared between the two conditions. Of these, the trunk and shoulder showed significant increases in movement while elbow showed significant reduction of motion.

DISCUSSION

Time

When the wrist was immobilised, there were significant increases in performance time for all subtests except test 6: placing light cans. Since the Jebsen hand function test is a simulation of common occupational performance tasks, it may be inferred that when the wrist is immobilised, an elderly person is likely to take a significantly longer time to perform everyday tasks.

When the time scores in this present investigation were compared with past studies, both similar and distinct findings were noted. The overall significant increase in time in the immobilised condition agreed with the findings of past investigations by Carlson et al. (1983) and Stern (1991). Both studies had been conducted on a younger population. It therefore appears that wrist immobilisation significantly increases the time taken for performance, regardless of one’s age group. Nevertheless, though the immobilised condition resulted in statistically significant increases in time, the difference amounted to less than two seconds for any activity for both Carlson et al. (1983) and Stern (1991) (mean differences were 0.85 and 0.45 seconds respectively). The differences in time for the elderly males in this study are comparatively higher, with the highest difference to be 3.39 seconds (mean difference was 1.60 seconds). This higher mean difference could imply that wrist immobilisation may have a greater impact on the elderly population, especially if they are also limited by other conditions such as poor endurance or general weakness in the body. When therapists apply splints to elderly clients, they perhaps should allow for a longer time for performance of occupational tasks.

Although most activities appear to require a significantly longer time to complete in the immobilised condition, Stern (1991) noted no significant increase in the time for tests that only required gross grasp and release (test six and seven). In this study, only test six: picking up light cans showed no significant increase. In the light of the results in this study, it may be proposed that in the elderly, the time to perform light-weighted activity involving gross grasp and release is not significantly increased by wrist immobilisation but resistive activity of the same nature does.

Compensatorymovement

While both past studies by Carlson (1983) and Stern (1991) and this study revealed significant differences in performance time on the JHFT between the two conditions, this study went beyond looking at the speed and investigated the altered upper limb movement patterns using the 3D upper limb measurement system. Visual inspection of the mean motion scores in the various parts of the upper limb indicated that subjects tend to increase trunk and shoulder motion when the wrist was immobilised. Elbow movement, on the other hand appeared to decrease during wrist immobilisation.

The increases in trunk and shoulder motion supported the proposition of past studies that wrist immobilisation results in accommodation of the above joints (Barr & Swan, 1988; Carlson, et al., 1983; Linscheid, et al., 1976; Perry, 1978). Specifically, it was found from this study that compensatory movement in the trunk was made predominately in the form of increased trunk rotation rather than side flexion (mean increase of 3.07 vs 0.92 in trunk flexion). This may be due to the fact that the average range of motion in the thoracic spine of an individual is greater for rotation than side flexion (Magee, 1987). Those tasks that required the subjects to cross the midline showed the greatest difference in trunk rotation when the wrist was immobilised (eg. Test 2: turning over cards and test 6 and 7: lifting light and heavy cans)

While trunk rotation and shoulder movement increased for most subtests in the immobilised condition, the elbow showed a distinct pattern of compensation: reduction of motion in most of the subtests. Stern (1991) suggested that movement of the elbow and shoulder becomes more important when the wrist is immobilised. Millender et al. (1973) and Linscheid et al. (1976) also proposed that immobilisation of the wrist places greater demands on other parts of the upper limb, especially the shoulder and the elbow, in positioning the hand. Although most authors have cited the elbow as one of the sources of compensatory joint motion during wrist immobilisation, the general assumption was that joint movement increases rather than decreases. The reduction of elbow motion as a compensation, which was found in this study is unexpected. It appears that immobilisation of the wrist somehow also restricted the elbow, possibly due to their proximity. It is possible that when the wrist is immobilised, the elbow and wrist move as a functional unit, resulting in a reduction of elbow motion. Further research is required to investigate this proposition.

It is interesting to note that while the differences in the total amount of motion in the shoulder and elbow were statistically significant when compared collectively for all the tests, analysis across each subtest showed that the majority of them do not differ significantly. With the significant level set at 0.05, only one out of seven tests (test five: stacking checkers) showed a significant increase in shoulder movement. In the elbow, two out of seven tests showed significant reduction in motion when the wrist was immobilised. It is possible that the significance in the first analysis was solely due to the few tests that were found to be statistically significant in the second analysis. However, it was the researchers’ opinion that the statistical analysis alone does not give the full picture of the effect of wrist immobilisation on the proximal joints of the upper limb. Some trends that appear to exist among the subjects are either not revealed at all by the statistical analysis or found to be statistically insignificant.

The lack of significance in the results may be attributed to various factors. First, great variability appears to exist among the subjects, both in the joint, the range and the mechanisms of compensation. Some subjects may compensate predominantly in a single joint while others may adapt in a global way. Not only do the site and mechanism of compensation vary between subjects, they also appear to vary according to the nature of the tasks attempted. Polgar and Thomas (1991) listed high variability of data as one of the reasons why researchers may obtain a null result. Trends that are subtle may be another reason. In such cases, a larger sample than that used in this study may be necessary to detect these subtle trends.

One of the most striking results of the study was the great variation in the effect of wrist immobilisation on the compensatory patterns of the upper limb joints. To further explore the variability of the upper limb movement patterns, a qualitative research method was used in addition to those described above because a) there is little information on the nature of movement pattern in the upper limb during activities of daily living and during wrist immobilisation; b) it would allow the generation of hypotheses so that future studies may be conducted. Specifically, content analysis in the form of visual inspection of the data for common themes and characteristics were performed. From there, three main patterns were noted and a further exploratory investigation was done in the form of a case study from each of the three pattern groups. These findings are reported elswhere (Chan & Chapparo, 1997).

Clinicalimplication

The results of this study remind therapists to be aware of the increased time factor when working with clients experiencing acute loss of wrist motion. It is important that not only the therapists but also the clients, are aware of this time increase. In this way, clients will not have unrealistic expectations of orthotic intervention that immobilises the wrist, which may reduce their acceptance of the orthosis and thus compliance to treatment.

The link between three constructs studied in this research: time, biomechanical component ability and occupational task performance is congruent with the same hypothetical relationships outlined in the Occupational Performance Model (Australia) (Chapparo & Ranka, 1996). One assertion in the model is that occupational tasks are to a certain extent dependent on efficient biomechanical function. Where biomechanical function is compromised, it is possible that performance of occupational tasks, also will be compromised. In this study, that relationship is demonstrated. Where biomechanical efficiency of the wrist is compromised by immobilisation, so too, is efficient performance of some occupational tasks. Similarly, time is viewed as an important construct in occupational performance. The relationship between timing of movement and timing of occupational tasks has also been illustrated in the results of this study.

It can be suggested from this study that the shoulder appears to be the major compensatory joint during wrist immobilisation by increasing motion for most activities. By increasing the strength or range of motion at the shoulder, it may potentially contribute to the adaptations of loss of wrist motion. However, further research needs to be carried out to investigate whether this trend is consistent over time and if it is beneficial to the outcome of splinting and wrist fusion. Similar suggestions may be made for the trunk as it also showed relatively consistent increases in motion in the immobilised condition.

The results of this study illustrate the interdependence of upper limb joints. When the wrist is immobilised, the rest of the upper limb also appeared to be affected. When therapists immobilise a client’s wrist, attention must be paid to the other upper limb joints too.

The upper limb measurement system developed from this study could be used for a wide range of purposes and may have broader applications for studying other aspects of occupational performance. First, basic kinematic studies on the movement of the upper limb during a wider range of occupations will increase the knowledge and understanding of normal upper limb movement. This may include resistive activities and activities not limited to the tabletop. Developmental research may also be conducted to investigate how hand and upper limb function change over time.

Second, the system may be used in clinical research to investigate the differences between normal and “abnormal” upper limb movement. For instance, cerebral vascular accident is one of the most prevalent diseases that strikes the adult population in the present society. Many clients do not fully recover upper limb and hand function (Pedretti, 1990). Research is needed to compare the three-dimensional kinematics of the upper limb in these client groups with normal subjects to identify those dysfunctional components. Similarly, this system may be used to increase understanding about other diseases and conditions that affect the performance of the upper limb.

Third, further research investigating the effects of other orthotic systems on upper limb function may be conducted. This may include other orthoses systems besides wrist hand orthoses This knowledge will assist therapists and orthotists in their understanding and prescription of orthotic intervention.

LIMITATIONSAND RECOMMENDATIONS FOR FUTURE STUDIES

This study was limited to researching the effect of wrist immobilisation on the proximal joints of the upper limb. It is suggested that further analysis be performed on the data to include the movement patterns in the distal joints of the hand. This will give a fuller and more detailed picture of the effect of wrist immobilisation on the upper limb.

Only the absolute degree of motion occurring at the proximal joints of the upper limb was monitored (e.g. wrist extension/flexion, ulna/radial deviation are quantified as an absolute value). The aim of the study was to determine in a general sense if there is a difference in the proximal three-dimensional upper limb movement between the free and immobilised condition, and the relative angles of the upper limb segments were not studied. More indepth analysis of the data may allow the functional range of motion occurring at the upper limb joints during activities of daily living to be quantified.

The wrist hand orthoses applied to the subjects were not custom fit. This may have reduced the ability of the orthosis to fully immobilise the wrist. To address this problem, careful balance was struck by tightly strapping the orthosis to minimise wrist motion without inflicting pain or discomfort to the subjects. Future studies may want to explore the use of other orthotic devices that can fully immobilised the wrist, such as casting, or the gauntlet system

Due to time and resource constraints, the sample has been restricted to nine subjects. By establishing conservative significance levels for statistical test (0.05 or less) and controlling extraneous variables, unfounded generalisations to the larger population is controlled. The results however, do highlight the variability of upper limb movement and its compensatory patterns. Further research in this area is definitely warranted using larger samples to substantiate the findings. Alternatively, multiple replication of research carried out on small sample sizes may also further the investigations in this area.

Finally, in any kinematic study utilising motion analysis systems and skin markers, there are errors in the data that have to be taken into account. These include inaccuracy in calibrating the ExpertvisionTM system, marker obstructions, skin movements and idealisation error. Although all efforts were taken by the researcher to reduce these errors, future replication studies could serve to validate the accuracy of the data obtained using this measurement system.

CONCLUSION

Based on the results of the study, wrist immobilisation appears to affect both the timing and range of motion of the upper limb in elderly males during performance of the Jebsen Hand Function Test. The differences in time for the elderly sample were comparatively higher than past studies on younger populations, suggesting wrist immobilisation may affect elderly to a greater extent. In general, there were compensatory increases of motion at the shoulder and decreases motion at the elbow during wrist immobilisation. The study also validated the use of the upper limb measurement system that was developed in this study using the ExpertvisionTM. It has the ability to diffferentiate between the movement patterns of the upper limb during free and immobilised wrist condition and could have numerous applications in future occupational therapy research on the performance of upper limb occupations.

ACKNOWLEDGEMENTS

The authors acknowledge the contributions made by the nine voluntary participants; Richard Smith and the Biomechanics Department of The Faculty of Health Sciences; to John Balla, for his statistical advice and to the School of Occupational Therapy, The University of Sydney, for partially funding the resources required for completing the study.

REFERENCES

Backman, C., Mackie, H., & Harris, J. (1991) Arthritis hand function test: Development of a standardized assessment tool. TheOccupational Therapy Journal of Research. 11(4), 246-255 Barr, N.R., & Swan, D. (1988)The hand: Principles and techniques of splintmaking. (2nd. Ed.). Sydney: Butterworths

Brand, P.W., (1985) External stress: Forces that affect joint action. In P.W. Brand (Ed.). Clinical mechanics of the hand. (pp.105-112). St. Louis: C.V. Mosby Co. Carlson, J.D., & Trombly, C.A. (1983) The effect of wrist immobilization on performance of the Jebsen Hand Function Test. American Journalof Occupational Therapy, 37(3), 167-175

Carr, J. & Shepherd, R. (1987) Upper limb function. In Carr, J. & Shepherd, R. A motor relearning programme for stroke. (2nd Ed.). (pp.43-72). Rockville: Aspen Systems Chan, W., & Chapparo, C. (1997). The effects of wrist

immobilisationon upper limb function in elderly males. OT Australia, AAOT. The 19th Federal Conference. Perth, April.

Chapparo, J. & Ranka, J. (1996) The occupational performance

model(Australia). Draft manuscript. (Available from The School of Occupational Therapy, Faculty of Health Sciences, The University of Sydney. Lidcombe. 2141. NSW) May.

Charness, A.C., (1988) Stroke head injury: A guide to functional outcomes inphysiotherapy management. MD: Aspen Publishers Inc.

DeLozier, G.S., Alexander, I.J., & Narayanaswamy, R. (1991) A method for measurement of integrated foot kinematics. Proceedings of theInternational Symposium on #-Dimensional analysis of human movement.Montreal: Canada, 79-82.

Feldon, P. (1988) Wrist fusions: Intercarpal and radiocarpal. In

D.M. Licktman (eds.). The wrist and its disorders (pp. 446-463) Philadelphia: W.B.Saunders

Fess, E.E. (1986) The need for reliability and validity in hand

assessment instruments. The Journal fo Hand Surgery, 11A(5), 621-623

Gant, R. (1993) The accuracy and reliability of a method

measuringthe three-dimensional kinematics of the foot during the stance phaseof walking, and its application to patients with osteoarthritis ofthe knee. Unpublished Masters Thesis. (Available from The Faculty of Health Sciences, The University of Sydney, Lidcombe, NSW 2141)

Hackel, M.E., Wolfe, G.A., Bang, M.S., & Canfield, J.S. (1992)

Changes in hand function in the aging adult as determined by the Jebsen Hand Function Test. Physical Therapy, 72(5), 373-373

Jebsen, R.H., Taylor, N., Trieschmann, R.B., Trotter, M.J., &

Howard, L.A. (1969) An objective and standardized test of hand function. Archives of Physical Medicine and Rehabilitation, 50(6), 311-319

Kraft, G.H., & Detels, P.E., (1972) Position of function of the wrist. Archives of Physical Medicine and Rehabilitation, 53, 272-275

Kreighbaum, E., & Barthels, K.M. (1985) Biomechanics: A

qualitativeapproach for studying human movement. (2nd Ed.). Minneapolis: Burgess Publishing Co.

Lehmkuhl, L.D., & Smith, L.K. (1983) Brunnstrom’s clinical

kinesiology.(4th ed.). Philadelphia: F.A. Davis Co.

Linscheid, R.L. & Beckenbaugh, R.D. (1976) Total arthroplasty of the wrist to relieve pain and increase motion. Geriatrics, 4. 48-52

Magee, D.J. (1987) Thoracic (dorsal) spine. In D.J. Magee:

Orthopedicphysical assessment. (pp. 142-169). Philadelphia: W.B.Saunders

Malick, M.H. (1988) Upper extremity orthotics. In H.L. Hopkins & H.D. Smith (Eds.). Willard & Spackman’s occupational therapy. (7th Ed.). (pp. 308-316). Philadelphia: J.B. Lippincott Co.

Millender, L.H. & Nalbuff, E.A. (1973) Arthorodesis of the

rheumatoid wrist. Journal of Bone and Joint Surgery, 55A, 1026-1034

Motion Analysis Expertvision System TM (1989) Motionalanalysis corporation. 3650 North Laughlin Rd., Santa Rosa. California. USA.

Moseley, L (1992) Three dimensional kinematics of the rear foot during thestance phase of walking at three dirfferent velocities. Unpublished Honours Thesis. (Available from The Faculty of Health Sciences, The University of Sydney, Lidcombe, NSW.)

Perry, J. (1975) Pathomechanics. In American Academiy of

Orthopedic Surgeons, Atlas of orthotics: Biomechanical principles andapplication (pp. 57-64). St. Louis: C.V. Mosby.

Perry, J. (1978) Normal upper extremity kinesiology. Physical

Therapy,58,(3), 265-278

Polgar, S., & Thomas, S.A. (1991) Introduction to research in thehealth sciences. (2nd Ed.). Melbourne: Churchill Livingstone

Rossi, J. (1988) Concepts and current trends in hand splinting.

OccupationalTherapy in Health Care. 4(3/4), 53-67

Sarrafian, S.K. (1975) Functional anatomy of the upper limb. In American Academy of Orthopedic Surgeons. Atlas of orthotics: Biomechanicalprinciples and application (pp. 33-56) St. Louis: C.V> Mosby Co.

Stern, E.B. (1991) Wrist extensor orthosis: Dexterity and grop

strength across four styles. American Journal of Occupational Therapy,45,(1), 42-49

VanderLinden, D.W., Carlson, S.J., & Hubbard, R. (1992)

Reproducibility and accuracy of angle measurement obtained under static conditions with the Motion Anlysis System.Physical Therapy, 72, 300-305

Marker Number	Site
1	2 cm below clavicle at left mid clavicular line.
2	Perpendicular intersection of 1 and 3, approximately at sternal angle.
3	Body of sternum
4	15 centimetres above Marker 6, along lateral border of arm.
5	10 cm above Marker 6, along medial border of the arm.
6	Lateral epicondyle of elbow.
7	Styloid process of radius.
8	Head of ulna.
9	MCP joint of thumb.
10	IP joint of thumb.
11	MCP joint of index finger.
12	PIP joint index finger.
13	DIP joint of index finger.
14	MCP joint of little finger.

Table2: Descriptive and statistical data: performance time (in seconds)during JHFT in free (F) and immobilised (I) conditions

 	Mean	S.D.	Mean of difference (F-I)	S.D.	One tailed t-value (df= 8)
Test 1: writing F: I:	16.00 17.95	2.56 3.20	-1.95	1.93	-6.06 **
Test 2: turning over cards F: I:	8.51 10.52	2.52 2.61	-2.62	3.77	-4.18 *
Test 3: picking up small objects F: I:	6.79 7.50	0.92 1.10	-0.62	0.83	-4.34 *
Test 4: simulated feedingF: I:	9.52 12.91	1.24 2.61	-.3.39	2.71	-7.52 *
Test 5: stacking checkersF: I:	5.82 6.71	1.05 1.42	-0.89	1.00	-5.32 *
Test 6: picking up light cansF: I:	5.54 6.06	0.73 0.78	-0.51	0.84	-3.64
Test 7: picking up heavy cans F: I:	7.34 8.55	1.05 1.40	-1.21	0.72	-10.08 ***

* Significant at 0.05 level

** Significant at 0.01 level

*** Significant at 0.001 level

Table3: Mean of total degree of motion of each component (in degrees) +standard deviation for Test 1-7 in free (F) and immobilised (I)conditions

 	Mean	Standard deviation	z-value	2-tailed p value (df=8)
Rotation of trunk	F:87.48 I: 107.18	19.89 27.14	-1.68	0.09
Side flexion of trunk	F:78.99 I: 83.44	25.18 33.50	-0.70	0.48
Shoulder	F:76.63 I:83.79	14.11 15.94	-2.03	0.04*
Elbow	F:133.74 I: 114.97	13.63 4.66	-2.37	0.02*

* Significant at 0.05 level

Table4: Mean of degree of motion (in degrees) + standard deviationin the free (F) and immobilised (I) condition

 

Components of the upper limb

Test no.	Rotation of trunk	Side flexion of trunk	Shoulder	Elbow
1: writing F: I:	12.80+2.99 12.65+4.65	9.15+4.32 10.08+4.74	7.19+3.99 6.74+3.17	6.35+2.59 6.74+1.74
2: turning over cards F: I:	14.95+3.97 21.75+10.63	26.54+11.57 27.18+12.42	12.97+2.60 15.20+3.74	18.55+7.31 12.84+4.45
3: picking up small objects F: I:	10.28+2.51 12.54+4.70	8.55+4.75 8.77+3.53	10.27+2.48 12.36+2.89	10.25+3.60 11.50+4.32
4: simulated feedingF: I:	12.37+3 52 15.24+5.68	9.39+3.61 10.53+3.58	9.48+3.69 13.29+7.73	43.96+9.11 37.69+10.19
5: stacking checkersF: I:	14.74+3.89 15.99+7.23	7.61+2.24 9.30+6.84	14.82+3.35 18.22+3.48	14.39+2.99 12.80+1.66
6: picking up light cans F: I:	15.78+5.20 20.29+5.84	11.27+4.59 13.62+4.98	8.77+2.46 9.61+2.05	20.51+4.01 20.46+3.70
7: picking up heavy cans F: I:	18.18+7.91 22.17+5.50	13.25+4.99 13.22+4.83	9.79+1.88 9.29+1.18	18.89+4.84 18.73+3.56

Table5 : Mean of free minus immobilised degree of motion in trunk rotationand side flexion, standard deviation, z-value and 2-tailed p-value

Test no.	Mean+ Standard deviation	z value	2-tailed p-value
1. Writing	Rotation: 0.14 + 4.58 Sideflex: – 0.93 + 6.15 Shoulder: 0.45 + 2.16 Elbow: -0.39 + 2.47	-0.30 -0.41 -0.77 -0.30	0.76 0.68 0.44 0.77
2. Turning over index cards	Rotation: -6.80 + 11.15 Sideflex: -0.64 + 8.84 Shoulder: -2.15 + 30-.84 Elbow: 5.48 + 6.13	-1.40 -0.14 -1.82 -2.37	0.16 0.89 0.18 0.02
3. Picking up small objects	Rotation: -2.27 + 5.95 Sideflex: -0.21 + 4.82 Shoulder: -2.09 + 2.54 Elbow: -1.25 + 2.49	-0.65 -0.06 -1.82 -0.98	0.51 0.95 0.07 0.33
4. Simulated feeding	Rotation: -2.87 + 6.58 Sideflex: -1.14 + 4.51 Shoulder: -3.81 + 6.80 Elbow: 6.27 + 6.18	-1.24 -1.01 -1.40 -2.10	0.21 0.31 0.16 0.04 *
5. Stacking checkers	Rotation: -1.25 + 9.71 Sideflex: -1.69 + 6.93 Shoulder: -3.40 + 2.82 Elbow: 1.59 + 2.83	-0.18 -0.06 -2.55 -1.60	0.86 0.95 0.02 * 0.11
6. Placing light cans	Rotation: -4.51 + 6.96 Sideflex: -2.35 + 2.82 Shoulder: -0.82 + 2.72 Elbow: 0.05 + 3.92	-1.71 -2.07 -1.24 -1.18	0.09 0.04 * 0.21 0.86
7. Placing heavy cans	Rotation: -3.98 + 7.23 Sideflex: 0.53 + 4.46 Shoulder: 0.49 + 2.13 Elbow: 0.16 + 3.98	-1.60 -0.30 -0.89 -0.41	0.11 0.77 0.37 0.68

Significant at 0.05 level