Forces women with arthritis use to access or operate containers free-handed and when using wrist orthoses

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1 The University of Toledo The University of Toledo Digital Repository Master s and Doctoral Projects Forces women with arthritis use to access or operate containers free-handed and when using wrist orthoses Chase A. Majewski The University of Toledo Follow this and additional works at: This Scholarly Project is brought to you for free and open access by The University of Toledo Digital Repository. It has been accepted for inclusion in Master s and Doctoral Projects by an authorized administrator of The University of Toledo Digital Repository. For more information, please see the repository's About page.

2 Running Head: FORCE REQUIRED TO ACCESS OR OPERATE CONTAINERS 1 Forces Women with Arthritis Use to Access or Operate Containers Free-handed and when Using Wrist Orthoses Chase A. Majewski Research Advisor: Julie J. Thomas, Ph.D., OTR/L Occupational Therapy Doctorate Program Department of Rehabilitation Sciences The University of Toledo May 2013 This scholarly project reflects individualized, original research conducted in partial fulfillment of the requirements for the Occupational Therapy Doctorate Program, The University of Toledo.

3 FORCE USED TO ACCESS OR OPERATE CONTAINERS 2 Abstract Objective This study examined the effects of wearing a wrist orthosis on the amount of force women with arthritis use to open or access common household containers. Method A sample of 60 women aged 55 and older with a diagnosis of arthritis participated in the opening and accessing of six common household containers with the free hand and again while wearing a wrist orthosis. The amount of force exerted on the containers was measured using Force Sensing Resistors. Results The mean amount of force exerted on the different containers ranged from 7.74 pounds to pounds within the sample. No significant differences (p>.05) in the amount of force exerted to open or access containers were observed when using the free hand compared to when wearing the wrist orthosis. Effect sizes for each of the containers were negligible, ranging from.01 to.20. Conclusion According to the present study, the use of a wrist orthosis produces no significant difference in the amount of force used to access or open certain common household containers among women aged 55 and over with a diagnosis of arthritis. Additionally, the amount of force used to access containers within the study may be used by occupational therapists to suggest use of containers that require less force to their clients with diagnoses of arthritis. Future research could involve additional containers or tools that involve use of the hand and wrist. Also, additional demographic groups should be explored as well, including males.

4 FORCE USED TO ACCESS OR OPERATE CONTAINERS 3 Force Women with Arthritis Use to Access or Operate Containers Free-handed and when Using Wrist Orthoses Many individuals may take for granted the ability to access containers for use in daily occupations. By exploring grip and pinch strength scores, we can see that as people age, their strength tends to decrease. Strength may decrease even more in individuals with arthritis. To help alleviate the pain caused by arthritis, a wrist extension orthosis may be used. Previous studies show the effect of using a wrist orthosis on grip and pinch strength, range of motion, and functional hand use. The purpose of this study was to explore the effects that wearing a wrist orthosis may have on the amount of force generated to access common household containers. Occupational therapists assist individuals in occupations of daily living. To be independent, clients must be able to manipulate and use objects related to occupations of daily living. For older adults experiencing pain and stiffness in joints of the wrist and hand from arthritis, these objects, specifically household containers, may prove to be difficult to access. There are many factors associated with hand use. Those include but are not limited to grip and pinch strength, dexterity, coordination of muscles, and in this case, orthosis use. Literature related to each of these topics is explored in the following review. Grip and Pinch Strength Grip and pinch strength for older adults generally decreases with age. Desrosiers, Bravo, Hébert, and Dutil (1995) reported mean grip strength norms that were established using a Jamar dynamometer for older adults over the age of 60. They found decreases in mean grip strength as age increases after 60. In a similar study, Stegink Jansen, Niebuhr, Coussirat, Hawthorne, Moreno, and Phillip (2008) found that among older individuals aged and over, both grip

5 FORCE USED TO ACCESS OR OPERATE CONTAINERS 4 and pinch strength significantly decreased with progressing age. This shows that the maximum amount of force available to older individuals declines over time, whether they have arthritis or not. The use of a wrist orthosis may reduce pain in the joints and provide leverage for the strength that they still have available. Type of Wrist Orthosis For older individuals with arthritis, a wrist orthosis is successful in reducing pain and allowing as much hand use as possible. A commonly used wrist orthosis is the Rolyan D-Ring wrist extension orthosis. Previous studies have explored the effects of using different prefabricated orthoses, including the Rolyan D-Ring. Collier and Thomas (2002) reported that wearing the D-Ring allowed significantly more palmar flexion of the wrist among adult females when shooting a basketball, but significantly less dorsiflexion than that provided by a custom made wrist orthosis. Stern (1996) compared the use of five wrist orthoses in terms of grip strength among adult right-handed women. Participants produced grip strength measurements when wearing the Rolyan D-Ring orthosis that were similar to the strength produced by their free hands. She also reported that grip strength was significantly greater when using the Rolyan D-Ring compared to the four other commercially available prefabricated wrist orthoses, including the Futuro wrist brace, both AliMed short and long braces, and the LMB Wrist Rest.

6 FORCE USED TO ACCESS OR OPERATE CONTAINERS 5 ROM with Wrist Orthosis A wrist extension orthosis can have an effect on performance when compared to performance with the free hand. In terms of range of motion, King, Thomas, and Rice (2003) found that among younger adults, wearing a wrist orthosis resulted in significantly more shoulder flexion and abduction than free-handed in completing a simple pouring task. This can be expected as the shoulder can be used to compensate for lack of range of motion in more distal upper extremity joints, including the wrist. A difference in wrist range of motion occurs when wearing a wrist orthosis as well. Collier and Thomas (2002) compared four different orthoses among younger adults shooting a basketball and found that each orthosis led to significantly less motion at the wrist than the free hand. Both static and dynamic wrist orthoses worn for everyday tasks have an effect on the ability to complete tasks by decreasing the range of motion available to a person. The advantage afforded by wearing a wrist orthosis for individuals with arthritis includes a decrease in pain and discomfort. These benefits need to be balanced with the loss of range of motion that results from wearing a wrist orthosis. Grip and Pinch Strength with an Orthosis A consideration of providing an orthosis to a patient is the effect it has on grip and pinch strength. An individual wearing a wrist orthosis may experience decreased grip and/or pinch strength when compared to using the free hand. Johannson, Björing, and Hägg (2004) studied middle-aged individuals in terms of muscle activity of wrist flexors and extensors, but also found a decrease in grip strength among individuals when using both rigid and flexible wrist orthoses. A decrease in strength is natural as people age. In older individuals with arthritis, wearing a wrist orthosis may be beneficial by helping to preserve their ability to grip while decreasing pain.

7 FORCE USED TO ACCESS OR OPERATE CONTAINERS 6 A wrist orthosis provides the support needed to grip by keeping the joints causing pain immobile or greatly reducing their range of motion. Effect of Wrist Position on Grip Strength The effect of wrist position is important to consider when measuring grip strength. Different positions of the wrist affect available grip strength due to tendon stretch of the muscles used in measuring grip strength. O Driscoll, Horii, Richards, and An (1992) found differences in hand grip strength, measured by a Jamar Dynamometer, among individuals at different wrist positions of flexion/extension and ulnar/radial deviation. They found that a self-selected position of 35 of wrist extension and 7 of ulnar deviation resulted in the greatest grip strength output. In a later study, Fong and Ng (2001) found the optimal wrist positions to achieve maximum grip strength to be at 15 of extension and neutral or 0 of radial and ulnar deviation. Li (2002) reported strongest individual finger forces in the index, long, ring, and small fingers when the wrist was placed in a position of 20 of extension and 5 of ulnar deviation. Among these studies, individuals with wrists in positions of some extension led to greatest grip and individual finger strength. Therefore, when providing a wrist orthosis for a patient with arthritis, occupational therapists should position the wrist at of extension and no more than 5 of ulnar deviation in order to allow the client maximum pinch and grip strength. Functional Hand Use with an Orthosis Hand dexterity should also be considered for individuals wearing wrist orthoses. A common way to assess functional hand use in the clinic is by using the Jebsen hand function test. Stern (1991, 1996) conducted two studies regarding the effects of wearing different orthoses on grip strength and dexterity among younger adult women. She found that individuals using the

8 FORCE USED TO ACCESS OR OPERATE CONTAINERS 7 free hand scored better on the Jebsen hand function test than individuals using any orthosis. She also found that the free hand produced higher maximum grip strength than when wearing any of the orthoses included in the study. Carlson and Trombly (1983) studied functional hand use and found that for younger adults, wearing a wrist orthosis led to a significant increase in the amount of time needed to complete the Jebsen hand function subtests when compared to using no wrist orthosis. So, not only does a wrist orthosis reduce the strength of grip and pinch, but it may also decrease an individual s speed in manipulating objects. Accessing Containers Occupations of daily living require the ability to access and operate containers used for self-care and for household tasks, such as cleaning. Rice, Leonard, and Carter (1998) tested younger adults in terms of grip strength and the forces required to access certain household containers. They determined that there is a significant difference between genders in terms of the maximum amount of grip and pinch forces, but not for the amount of force exerted to access the containers. They found little relationship between the total amount of grip strength possessed and the amount of force used to access the containers among all participants. They found averages ranging from 2.23 pounds of force, used in accessing a small prescription bottle, to pounds of force, used in accessing a pop off lid medicine bottle, were used to access common household containers. The most extreme amount of force was exerted on an aerosol spray bottle in an amount of pounds. From the data, the authors concluded that about 20 pounds of grip strength would be sufficient to access all containers tested for the majority of people. A grip strength of 20 pounds is easily achievable for many individuals without disability. Individuals with arthritis may be able to achieve this level of grip strength, but may experience significant pain at the same time.

9 FORCE USED TO ACCESS OR OPERATE CONTAINERS 8 Rahman, Thomas, and Rice (2002), tested individuals 60 years and older for grip and different pinch strengths and the amount of force used to access household containers. They found that elderly persons tend to use more of their available force to access containers than younger adults studied by Rice et al. (1998). Yet, their overall grip and pinch strength was less than the grip and pinch strength of the younger subjects in the Rice study. This suggests that the older individuals used more of their available force to access the containers. The mean forces that the older adults used ranged from 2.19 pounds, which was exerted on a small prescription bottle, to 9.76 pounds, which was exerted on a dual-pinch squeeze bottle. Unlike the Rice study, Rahman et al. reported a fair relationship between the forces used on two of the containers, the large prescription medicine bottle and the aerosol spray can, and the participants grip strengths. Also, pinch strength was found to have a fair relationship with the forces exerted on three of the containers, the dual-pinch squeeze bottle, the large prescription bottle, and the aerosol spray can. The maximum amounts of force exerted on these containers for this study ranged from 8.10 pounds for the small medicine bottle to 20 pounds of force for the aerosol spray bottle. Researchers have found that grip and pinch strength norms for older individuals are significantly lower than in younger individuals. Further decrease in strength can be seen in older individuals with arthritis. With a larger decrease in hand strength, functional hand use can decline as well. As seen from the studies involving the Jebsen hand function test, wearing an orthosis can increase the time needed to complete tasks. Although wrist orthoses are often used to decrease pain in patients who have arthritis, these decreases in range of motion and grip and pinch strength may significantly affect their ability to carry out their activities of daily living. Previous studies have explored the amount of grip and pinch strength required to access various household containers. There was very little correlation between the amount of grip

10 FORCE USED TO ACCESS OR OPERATE CONTAINERS 9 strength available to the participants and the amount that they used to access these containers (Rice et al, 1998; Rahman et al, 2002). However, older individuals accessing containers exerted more force than did younger adults. Researchers have explored the effects of wearing a wrist orthosis on grip strength, overall dexterity, and hand functioning. What hasn t been explored is the effect of wearing a wrist orthosis on the force used to access containers commonly used in self-care and household tasks. The purpose of this study was to explore the effects that wearing a wrist orthosis has on the forces used to access household containers among individuals with arthritis. Our hypothesis was that there will be a difference between individuals using a prefabricated wrist orthosis and using the free hand in terms of the amount of force used to access household containers. This study adds to the knowledge we have about the effects of wrist orthoses on the forces used to access containers. Method Participants Females over the age of 55 were recruited for the study. These individuals had a diagnosis of arthritis. Participants reported no other orthopedic or neuromuscular conditions affecting their upper extremities that would compromise their performance. All participants were English speaking. Participants were recruited from local northwest Ohio arthritis support groups, The University of Toledo Center for Successful Aging, and local Toledo, Ohio senior centers after permission was obtained from the facilities. Participants were also recruited from a study announcement at the local Arthritis Foundation. Recruitment methods included flyers and word of mouth.

11 FORCE USED TO ACCESS OR OPERATE CONTAINERS 10 Instruments Each participant was fit with the proper size Rolyan D-Ring wrist orthosis (shown in Figure 1) prior to obtaining any data in the orthotic conditions. Only the Rolyan D-Ring orthosis was used in order to standardize data collected and also because it is a commonly used wrist orthosis for persons with arthritis. Once fitted with the correct size wrist orthosis, each participant had the othosis adjusted so that wrist position was at 20 of extension (see Figure 1). A previous study indicated that this wrist position would produce maximal hand and finger force (Li, 2002). Wrist position was measured by a standard goniometer, using published criteria by Clarkson (2013), with one arm of the goniometer parallel to the ulna and the other parallel to the 5 th metacarpal. The axis for the goniometer was in line with the ulnar styloid process. A standard Baseline Digital Dynamometer was used to collect baseline grip strengths among participants. Also, a standard Baseline Digital Pinch Dynamometer was used to determine baseline pinch strengths in participants. Both the grip and pinch dynamometers were calibrated prior to obtaining measurements. Six common household containers were used in the study. They had force-sensing resistors (FSRs) attached to them to record the amount of force participants exerted while accessing the containers. These FSR s were placed on areas where force is used to access containers. The FSRs were calibrated and placed on containers before data were collected. Data obtained by the FSRs were interfaced with a custom computer data collection program. The containers used in this study, along with FSRs attached, are shown in Figure 2. The containers include: 1. Dual pinch safety squeeze bottle

12 FORCE USED TO ACCESS OR OPERATE CONTAINERS Small prescription bottle 3. Large prescription bottle 4. Over-the counter medicine bottle having a pop-off lid accessible after alignment of tabs 5. Aerosol can of air freshener requiring single hand operation involving a power grip and depression of a button by either the thumb or index finger 6. Pump spray bottle with trigger that requires single hand operation involving a power grip with either one or two fingers to pull the trigger Design This study used a repeated measures, counterbalanced design. A custom computer program randomized each participant into two different sets of container task conditions with and without the wrist orthosis, and also randomized each participant into an order of grip and pinch strength measurement sequence. Procedure The University of Toledo Institutional Review Board approved the study prior to data collection. The researcher obtained both written and verbally expressed informed consent from subjects prior to participating in the study. The researcher obtained demographic information after informed consent, which included age, ethnicity, hand dominance, and history of orthosis use. Participants were individually fit with a Rolyan D-Ring wrist orthosis of the appropriate size. The adjustable metal stay was shaped to position the wrist to 20 of extension prior to any measurements being taken.

13 FORCE USED TO ACCESS OR OPERATE CONTAINERS 12 Participants were randomized to a counterbalanced order of container task conditions using the wrist orthoses first. Participants then experienced another randomized order of the same containers again, this time without the wrist orthosis. Lastly, each participant experienced a counterbalanced order of hand strength measurements, all without the wrist orthosis, including: grip strength with dynamometer, lateral pinch strength with pinch meter, two point tip pinch with pinch meter, and three jaw chuck with the pinch meter. Standardized procedures of the American Society of Hand Therapists, as described by Mathiowetz, Kashman, Volland, Weber, Dowe, and Rogers (1985) were used to obtain each of the measurements. Each participant completed three trials for each container and three trials of each grip and pinch strength measurement with a 30 second rest period in between each trial. To obtain data on accessing containers, patients sat with feet flat on the floor in an chair, seated one foot away from a 32 high table on which all containers were placed. Each of the containers was numbered. The participant received the following verbal instructions: I want you to pick up the container marked (number of container) and access or operate the mechanism on the container. After the first time, please repeat twice more, for a total of three times. Participants accessed and operated each container three times with and without the orthosis, for a total of 6 trials for each container. Data Analysis The maximum efforts in each of the three trials for each condition were averaged into a single value for the orthosis condition and for the free-handed condition. These mean values were included in the statistical analyses.

14 FORCE USED TO ACCESS OR OPERATE CONTAINERS 13 Descriptive data (central tendency, range, standard deviations) were calculated for forces used to access the containers. Normalcy of data was also assessed as well as testing for order effects. A Wilcoxon Signed Rank Test for non-parametric data was used due to non-normalcy of data. In addition to the Wilcoxon Signed Rank Test, effect sizes were calculated. Results The participants included in the sample were 60 older adult women. Two participants were removed from the sample due to incomplete data. Participants who generated forces of over 50 pounds were considered outliers and force data over 50 pounds were eliminated, in order to follow with the maximum forces reported in a similar study by Rice et al. (1998). Lastly, all data generated from orthoses and no orthoses conditions of the dual pinch safety squeeze bottle were removed due to computer and/or force sensing resistor error. The remaining data set included 58 women who ranged from 55 to 90 years in age. The mean age of the sample was years old (SD = 9.28). In terms of hand dominance of the sample, 54 participants (93.1%) were right handed, and 4 (6.9%) were left handed. Three ethnicities were represented by the sample, including 46 individuals identified as Caucasian (79.3%), 11 participants identified as African American (19%), and one participant identified as Asian (1.7%). Interestingly, only two participants had worn wrist orthoses for their arthritis prior to this study. Description and Statistical Analyses of Forces The data were tested for order effects. No effects for order of containers or the orthoses/no orthoses order of conditions were found. Data were tested for normalcy with the Guassian distribution. Some data were found to be non-normal, so non-parametric testing was

15 FORCE USED TO ACCESS OR OPERATE CONTAINERS 14 used. The Wilcoxon Signed Rank Test analyzes the change in direction of data in two different directions. Within this study, this was appropriate to determine whether the force used to access each container was greater or less while wearing wrist orthoses compared to not wearing them. In addition to determining the direction of change, the Wilcoxon Signed Rank Test determines the magnitude of differences, which in this study would signify how much more or less force was used on each container when wearing wrist orthoses compared to not wearing them. The forces used by participants on the containers both with wrist orthoses and without are displayed in Table 1. The mean forces ranged from 7.74 pounds of force (for operating the pump spray bottle without orthosis) to pounds of force (for operating the pop-off lid bottle with orthosis). The minimum amount of force used to access the containers ranged from 0.05 pounds of force for the small prescription bottle with wrist orthosis to 6.85 pounds of force for the popoff lid bottle with no orthosis. The maximum amount of force ranged from pounds of force for the large prescription bottle without wrist orthosis to pounds of force for the popoff lid bottle with orthosis. The maximum amount of force used when operating containers with wrist orthoses was compared to maximum force used with the free hand (see Table 1) using the Wilcoxon Signed Rank Test. When operating the pump spray bottle, the mean amount of force used with orthoses was 7.93 pounds, compared to 7.74 pounds without wrist orthoses (p = 0.720). Operation of the aerosol bottle yielded a mean amount of force of pounds with wrist orthoses, while a mean of pounds of force was used without wrist orthoses (p = 0.513). When operating the small prescription bottle, the mean amount of force used with wrist orthoses was pounds, compared to pounds without wrist orthoses (p = 0.669). The mean force used to operate the pop-off lid bottle with wrist orthoses was pounds, while pounds of force was

16 FORCE USED TO ACCESS OR OPERATE CONTAINERS 15 used without wrist orthoses (p = 0.645). When operating the large prescription bottle, the mean amount of force used with orthoses was 8.55 pounds, compared to 8.98 pounds without wrist orthoses (p = 0.864). In summary, the Wilcoxon test revealed that the operation of each individual container did not produce significant differences in the amount of force used when wearing the wrist orthoses compared to the free-handed condition. Effect size d for each of the containers was calculated. The effect size for the pump spray bottle condition was 0.02, the effect size for the aerosol bottle was 0.06, the effect size for the small prescription bottle was 0.01, the effect size for the pop-off lid bottle was 0.02, and the effect size for the large prescription bottle was According to the effect size classifications provided by Cohen (1988), effect sizes less than 0.20 are classified as small. The effect sizes found in this study are considerably less than 0.20 and can be classified as negligible. Discussion The purpose of this study was to determine the effects of wearing wrist orthoses on the amount of force used to access everyday household containers. The mean amount of force used with wrist orthoses was then compared with the amount of force participants used to access the same containers without wearing wrist orthoses. As displayed in Table 1, there are no significant differences in force used to access containers when wearing wrist orthoses compared to the free hand. The p values range from for the small prescription bottle to for the large prescription bottle. None of the p values found were near the 0.05 alpha level needed to find significant differences. The mean forces participants used when wearing wrist orthoses compared to not wearing them across all

17 FORCE USED TO ACCESS OR OPERATE CONTAINERS 16 container conditions were within 0.5 pounds of each other, further indicating that there were no significant differences generated by wearing wrist orthoses. The effect sizes for the differences in forces used on each of the containers were negligible, which may indicate one of two possibilities. The first possibility is that the sample size was too small to detect differences that may have been there or that a Type II error occurred. The second and more likely possibility is that the lack of significant differences found within the sample for any container is a valid result and that the negligible effect sizes reflect the similarity in performance under orthoses and no orthoses conditions. The present study differs from studies that use standard dynamometry scores for dependent variables in that we did not examine maximum hand strength forces, instead, we examined submaximal forces that were used to access the containers. The amount of force required to access the containers was below the maximum available hand forces for the participants. The present study suggests that there is no difference in submaximal forces produced when wearing wrist orthoses when compared to the free hand during functional hand use to access or operate common containers. It may be that as individuals approach their maximum hand forces, differences in using wrist orthoses versus the free hand become more apparent. This cannot necessarily be concluded as the present study examined hand forces during a functional task while studies completed by Stern (1991, 1996) used standardized tests requiring maximal grip efforts. In contrast to other studies, this study was conducted with older women who had a diagnosis of arthritis in order to expand the results to a clinical population. Within this sample, the findings in this study are not consistent with those of previous studies. This study suggests

18 FORCE USED TO ACCESS OR OPERATE CONTAINERS 17 that within this clinical population, wearing wrist orthoses does not have a significant effect on the amount of forces used to access common household containers. Wearing a wrist orthosis has been shown to change individuals grip strength. Johannson et al. (2004) found a decrease in maximum grip strength among healthy adults when using wrist orthoses. Stern (1991) also found that the free hand produced stronger maximum grip strengths than when wearing four different styles of wrist orthoses in a population of younger adult women. However, when wearing the Rolyan D-Ring wrist orthosis, Stern (1996) found no significant differences in maximum grip strength produced when compared to the free hand, although the free hand still produced slightly higher grip strengths. The findings in the previous studies examined the relationship between maximum hand strength and the forces used to access containers. The previous studies also focused on healthy individuals without a diagnosis of arthritis. Stern (1991) examined the effects of wearing a wrist orthosis on functional hand use. Her results suggest that individuals using the free hand perform better on the Jebsen hand function test than individuals using any type of wrist orthosis. Carlson and Trombly (1983) examined the effects of wearing a wrist orthosis on Jebsen hand function test scores in healthy adults, and found that wearing a wrist orthosis led to a significant increase in time necessary to complete the test, thus resulting in poorer scores. While the Jebsen hand function test has been shown to be a reliable measure of overall hand function, the components of the test are simulated, while the present study measures actual hand function tasks, which may produce different results. Some participants took more than reasonable amounts of time to access the containers while wearing the wrist orthoses. The Jebsen hand function test bases its results on the time taken to complete functional tasks. Since time needed to access or operate the

19 FORCE USED TO ACCESS OR OPERATE CONTAINERS 18 containers was not a dependent variable within the present study, one cannot fully compare the results of these previous studies to the present one. Previous literature has described the effects of wearing a wrist orthosis in terms of functional use, range of motion, and hand strength. Overall, those studies concluded that wearing a wrist orthosis does have a negative effect on speed of functional hand use, range of motion, and maximum grip strength. Based on the findings in the previous studies, we predicted that wearing wrist orthoses would produce a difference in the amount of force used to access the containers; however, that was not the case in the present study. Implications for Occupational Therapy Practice This study has important implications for occupational therapy practice. The first of which is that when recommending wrist orthoses for client use, occupational therapists may not need to be concerned with a decrease in ability to access common household containers. As noted in previous studies involving wrist orthosis use, wearing a wrist orthosis has shown a negative effect on range of motion, maximum hand strength, and speed of hand function measured by the Jebsen hand function test. While these effects may be of concern to occupational therapists, the results from this study produced different results. The current study suggests that functional hand use involving the accessibility of common household containers may not be negatively affected by wearing a wrist orthosis. Clients with a diagnosis of wrist or hand arthritis who wear wrist orthoses may not encounter increased difficulty accessing containers. The sample that was used in this study consisted of women aged 55 and older with a diagnosis of arthritis. Throughout the study, many participants subjectively reported that they

20 FORCE USED TO ACCESS OR OPERATE CONTAINERS 19 experience some degree of difficulty in accessing household containers while at home. Many participants voiced that the pop-off lid bottle and the dual-pinch safety squeeze bottle were among those containers that were difficult to access. Even though they reported that these particular containers were difficult to access, the use of a wrist orthosis did not seem to affect the amount of force they used on the containers. All participants were successful in accessing and operating the study containers. This study documented the average and range of forces that older women with arthritis exerted on common household containers. By providing these values, occupational therapists now know which containers used in the study require the most force to access. Based on this, occupational therapists can recommend certain types of containers to their clients for easier use in the home. For example, the mean force used to access the pop-off lid container was pounds while wearing wrist orthoses. Compared to the large prescription bottle, on which participants exerted a mean force of 8.55 pounds with an orthosis, the pop-off lid container required much more force to access. Occupational therapists can make recommendations to transfer medication stored within a pop-off lid container into a re-labeled, empty, large prescription bottle to make access to medication easier. Additionally, the occupational therapist can recommend that clients request that their pharmacists place their medication in large prescription bottles rather than small ones. The large prescription bottle required less force to access than the small prescription bottle, possibly due to the larger surface area. The results of the present study also suggest that operating a pump-spray bottle requires less force than operating an aerosol bottle. The therapist can recommend that when shopping, participants purchase containers that have a pump-spray mechanism over aerosol bottles.

21 FORCE USED TO ACCESS OR OPERATE CONTAINERS 20 The results from the present study can help to determine when compensatory strategies may be indicated for older women with arthritis. Occupational therapists can use the information provided to recommend certain household containers that may require less force than others. When the occupational therapist uses hand strengthening exercises with a client, he/she should monitor progress to determine which types of containers may become easily accessible as strength increases. If hand strengthening is contraindicated for the client, the occupational therapist can explore compensatory strategies, such as recommending containers that require less force to access. Limitations Several limitations were present within this study. The sensors used to detect force were placed in the most optimal position to measure the individual forces required to access the container, but additional forces may have been used as well. For example, when accessing the small and large prescription bottles, a small tab on the side of the lid was pressed in order to release a twist off lid. When measuring the force, the sensor was placed on the tab and not the lid, so the force of pressing the tab was recorded, but the force used when twisting the lid off was not recorded. Due to technical difficulties, data were incomplete and should be considered a limitation of the study as well. Another limitation involves generalizing the study to all patients wearing wrist orthoses. While it was important to control for as many individual and demographic factors as possible, therapists should be careful to not generalize the results to all populations, as differences may be present. For example, the same results may not be found when testing older men with arthritis. However, the study did include diversity in terms of ethnicity, which allows generalization to

22 FORCE USED TO ACCESS OR OPERATE CONTAINERS 21 African Americans as well as Caucasians. Additionally, the results from this study should not be generalized to all wrist orthoses. The present study investigated the Rolyan D-Ring wrist orthosis only. Lastly, participants used a wide range of forces to access containers. For example, participants operating the pump-spray bottle exhibited forces ranging from 1.24 pounds to pounds, showing a large range of pounds. This suggests that individual differences may produce significant differences in the hand forces used. Suggestions for Future Research Within this study, participants were selected with specific age, gender, and diagnosis characteristics. Future research should continue to examine the use of wrist orthoses with samples consisting of males for comparison. It would be interesting to observe the differences in forces used with and without wrist orthoses among additional containers, especially since this study primarily used medication containers. Participants verbally expressed that they had difficulty accessing jars, soda bottles with caps, and soda cans with pull-up tabs. In addition to access of containers, operation of certain household devices would be interesting to observe. For example, the operation of a standard can opener, bottle opener, or manual corkscrew may produce results that differ from the current study. The comparison of forces while using various wrist orthoses other than the Rolyan D-Ring could be explored. Within this study, participants were allowed to use either hand to access containers and they were encouraged to do so in the most comfortable way possible. Perhaps controlling the method that they used to access the containers would produce different results.

23 FORCE USED TO ACCESS OR OPERATE CONTAINERS 22 Conclusions The purpose of the study was to determine the effects that wearing wrist orthoses had on the forces generated to access common household containers among older women with a diagnosis of arthritis. Within the sample, results indicate that use of wrist orthoses did not have a negative effect on the forces used to access common household containers. These results are different from the findings of other studies which examined other factors of hand use while wearing wrist orthoses, including maximum grip strength, range of motion, and speed of functional hand use. Occupational therapists can use the information presented in this study to allay their concerns about their client s ability to access common containers when prescribing a wrist orthosis. Additionally, occupational therapists can recommend containers with mechanisms for access that require less force than other mechanisms, such as a large prescription bottle over a pop-off lid bottle. Acknowledgements This study was made possible by grant funding from the Northwest Ohio Arthritis Association. We thank the Margaret Hunt Senior Center in Toledo, OH for providing a site for participant recruitment and data collection.

24 FORCE USED TO ACCESS OR OPERATE CONTAINERS 23 References Carlson, J., & Trombly, C. (1983). The effect of wrist immobilization on performance of the Jebsen Hand Function Test. American Journal of Occupational Therapy, 37(3), Clarkson, H. M. (2013). Musculoskeletal assessment: Joint motion and muscle testing (3rd ed.). Philadelphia, PA: Lippincott Williams & Wilkins. Cohen, J. (1988). Statistical power analysis for the behavioral sciences (2nd ed.). Hillsdale, New Jersey: Lawrence, Erlbaum Associates, Inc. Collier, S., & Thomas, J. (2002). Range of motion at the wrist: A comparison study of four wrist extension orthoses and the free hand. American Journal of Occupational Therapy, 56(2), Desrosiers, J., Bravo, G., Hébert, R., & Dutil, E. (1995). Normative data for grip strength of elderly men and women. American Journal of Occupational Therapy, 49(7), Fong, P., & Ng, G. (2001). Effect of wrist positioning on the repeatability and strength of power grip. American Journal of Occupational Therapy, 55(2), Johansson, L., Björing, G., & Hägg, G. (2004). The effect of wrist orthoses on forearm muscle activity. Applied Ergonomics, 35(2), doi: /j.apergo King, S., Thomas, J., & Rice, M. (2003). The immediate and short-term effects of a wrist extension orthosis on upper-extremity kinematics and range of shoulder motion. American Journal of Occupational Therapy, 57(5), Li, Z. M. (2002). The Influence of wrist position on individual finger forces during forceful grip. The Journal of Hand Surgery, 27A, doi: /jhsu

25 FORCE USED TO ACCESS OR OPERATE CONTAINERS 24 Mathiowetz, V., Kashman, N., Volland, G., Weber, K., Dowe, M., & Rogers, S. (1985). Grip and pinch strength: Normative data for adults. Archives of Physical Medicine and Rehabilitation, 66, O Driscoll, S. W., Horii, E., Richards, R. R., & An, K. N. (1992). The relationship between wrist position, grasp size, and grip strength. The Journal of Hand Surgery, 17A, Rahman, N., Thomas, J., & Rice, M. (2002). The relationship between hand strength and the forces used to access containers by well elderly persons. American Journal of Occupational Therapy, 56(1), Rice, M., Leonard, C., & Carter, M. (1998). Grip strengths and required forces in accessing everyday containers in a normal population. American Journal of Occupational Therapy, 52(8), Stegink Jansen, C., Niebuhr, B., Coussirat, D., Hawthorne, D., Moreno, L., & Phillip, M. (2008). Hand force of men and women over 65 years of age as measured by maximum pinch and grip force. Journal of Aging and Physical Activity, 16(1), Stern, E. (1996). Grip strength and finger dexterity across five styles of commercial wrist orthoses. American Journal of Occupational Therapy, 50(1), Stern, E. (1991). Wrist extensor orthoses: Dexterity and grip strength across four styles. American Journal of Occupational Therapy, 45(1), 42-9.

26 FORCE USED TO ACCESS OR OPERATE CONTAINERS Figure 1. Rolyan D-Ring Wrist Orthosis 25

27 FORCE USED TO ACCESS OR OPERATE CONTAINERS Figure 2. Data Collection Materials Including Containers 26

28 FORCE USED TO ACCESS OR OPERATE CONTAINERS 27 Table 1 Forces Used to Access Containers with and without Wrist Orthoses Container Condition n M SD Min Max Z p Pump Spray Bottle Orthosis No Orthosis Aerosol Bottle Orthosis No Orthosis Small Prescription Bottle Orthosis No Orthosis Pop-off Lid Bottle Orthosis No Orthosis Large Prescription Bottle Orthosis No Orthosis Note: Unit of measure is pounds