Facilitator for the Month | Shifa Ansari
Mumbai, India
The following article is an open-access article, published in The American Journal of Occupational Therapy, Volume 68, and Number 3 in May 2014.
Link to the complete article at the end of the post
Article Citation:
Introduction:
The computer mouse is the primary input tool for a video display workstation. Repetitive motions, awkward posture, and sustained muscle contractions during mouse use have been associated with carpal tunnel syndrome. Muscle loads at wrist extension increase when users perform double-clicking and dragging tasks with the mouse. The occupational therapist often recommends wrist splints to minimize carpal tunnel pressure. However, earlier studies have focused only on the effect of splint design in mouse control tasks, and limited research has focused on mouse design for patients with wrist splints.
AIM and issues addressed by the article-
What are the research question/aims and objectives of the article?
This study aims to examine the dorsal-based wrist splints and front-hump mice enhance computer task efficiency and comfort? Also, what kind of relationship exists between anthropometry measurements and computer task efficiency in computer users
Design of the study- it is non-randomization prospective cohort trials. (Level of evidence IInd)
Study methods- Factorial experiment
2 X 2 (Cutaneous Feedback X Hump Position)
Inclusion criteria: (1) Age >18 years (2) Right-hand dominant (3) no symptoms of discomfort, pathology, or sequelae related to the right upper extremity (4) No other physical dysfunctions (5) Experienced computer users: operating a computer at least 1 hour per day.
Participants were recruited by advertisements placed around the campus of Fu Jeng Catholic University and the order of the mice was randomly assigned to the participants.
Sampling: The sample size was 32 (2 dropouts reported) final sample size was 30 in which 19 women and 11 men have participated.
Hypothesis- H1: A volar based splint, compared with a dorsal-based splint, would reduce the cutaneous feedback at the wrist and thus interfere with computer task efficiency.
H2: A front-hump mouse would be more suitable for patients with wrist splints.
Assessment Tools 1. Efficiency: movement time data were examined by using (ANOVA) Analysis of variance
2. Satisfaction: using (QUEST-T) questionnaire scores which is Quebec User Evaluation of Satisfaction with Assistive Technology
3. Anthropometric measurements: length of the hand, length of palm, length of index finger, and width of hand recorded with digital clipper
Results showed that task efficiency (shorter movement time) was better with cutaneous feedback in the dorsal wrist-splint condition (mean [M] ± standard deviation [SD]=63.43 ± 63.4 ms) than without cutaneous feedback in the volar wrist-splint condition (M ±SD=67.26 ±12.53 ms) The result also indicated a significant negative relationship between movement time and length of index finger which disclosed that longer the index finger better the task efficiency.
Task efficiency was significantly better with rear hump mice (M ± SD 5 63.74 ± 10.33 ms) than with front hump mice (M ± SD 5 66.94 ± 10.48 ms
Total scores of the QUEST–T questionnaire were similar throughout experimental conditions and did not have significant differences Results found no interaction between the type of splint and mouse hump position on task efficiency. Neither type of splint nor hump position influenced user satisfaction
Limitations-
1. Limitations of the study include that all the participants were healthy and right-hand dominant.
2. In the future, adding participants with pain at the wrists or who are left-hand dominant will enlarge the scope of the study.
Conclusion- Dorsal wrist splints coupled with a rear-hump mouse provide sufficient cutaneous feedback and increase task efficiency. The study also recommends that the length of the index finger be the prime anthropometric measurement related to computer task performance for participants with a wrist splint
Implications for Occupational Therapy Practice- If computer tasks are a major daily client activity, clinicians should choose a dorsal wrist splint design and a rear-hump mouse to preserve the cutaneous feedback. And if a volar-based splint is desired, a rear-hump mouse offers a stable rest area for the fingers and facilitates coordination in mouse scrolling and clicking.
Facilitator’s comments-
The study has a specific background and explanation of rationale with clear research question Study design: A Factorial Experiment, the advantage of this study design is it allows the investigator to simultaneously assess the effects of two independent factors on the outcome. The data collected from this research give information on the effect of the interaction between the independent variables which enable us to examine the interaction effect that exists between factors. All procedures were performed by the same research assistant and supervised by a principal investigator. Since more than one assessor is involved this can introduced manual bias in the study.
The order of mice was randomly assigned to the participants with no regards to mice dimension (both the mice were relatively smaller than standard mice) which gave rise to confounding factors. Exclusion criteria for participants and Calculation of sample size are not mentioned
The splint was given at 20° wrist extension, which is ergonomically not suitable hence it is less likely to use it for computer task
This article is now open for discussion. Looking forward to getting the community involved in the discussion to support the growth of community professional relationship
P.S: Don’t forget to share your thoughts and views on it in the comment section below.
A Special thanks to Charmi Shah for providing the opportunity to share our ideas and knowledge in the Journal club.
About the facilitator - Shifa Ansari is currently pursuing a master’s in Occupational therapy (musculoskeletal sciences) from Mumbai and a private practitioner at Masina Hospital.
Greeting from Mumbai
Link for full article- https://doi.org/10.5014/ajot.2014.009928