Pain
Conditions
Brief summary
Awkward postures during computer keyboard use have been hypothesized to be one cause of musculoskeletal pain/discomfort as well as musculoskeletal disorders of the upper extremity (MSD-UE). Alternative computer keyboards purport to reduce musculoskeletal pain/discomfort and have been shown to change aspects of keyboard users' kinematics under laboratory conditions. However, research that has examined the effectiveness of alternative keyboards in reducing musculoskeletal pain/discomfort in the workplace is equivocal, and no study has examined the association between postures and musculoskeletal pain. The Aims of this 3-year prospective double cross-over trial are: 1) To examine the effectiveness of an alternative keyboard in reducing reports of pain over 6-months; 2) To examine the neutrality and stability of postures during keyboard use; and 3) To identify which postures are associated with lower levels of musculoskeletal pain. Seventy-five computer users will be randomly assigned to one of two keyboard use orders: Group 1 - AB (standard keyboard, alternative keyboard); Group 2 - BA (alternative keyboard, standard keyboard). All subjects will use their assigned keyboards for 6-months before switching to the next keyboard. Every week, subjects will report their musculoskeletal pain levels. Just prior to and just after each 6-month intervention subjects' kinematics performances on the keyboards will be recorded at the worksite using the Keyboard - Personal Computing Style (K-PeCS) instrument and in a laboratory setting using 3-dimensional motion capture technology. Aim 1: To examine the effectiveness of an alternative keyboard in reducing pain over 6-months. Hypothesis 1 (H-1) - At six months subjects using an alternative keyboard will have significantly lower musculoskeletal pain levels than when using a standard keyboard. Aim 2: To examine the neutrality and stability of postures during keyboard use. Hypothesis 3 (H-2) - Subjects using an alternative keyboard will have significantly more neutral postures than when using a standard keyboard at baseline and at 6 months Hypothesis 3 (H-3) - Subjects 6-months keyboarding postures will remain equivalent to the keyboarding postures documented at baseline.
Interventions
DEVICEAlternative Keyboard
Subjects use either a typical or alternative keyboard
Sponsors
National Institute for Occupational Safety and Health (NIOSH/CDC)
University of Pittsburgh
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
PREVENTION
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 65 Years
Healthy volunteers
Yes
Inclusion criteria
* Use a computer at least 20 hrs per week * Aged 18-65 * Experiencing some pain during computer use
Exclusion criteria
* Currently use an alternative keyboard * Serious trauma injury to the upper extremity * Rheumatic disorder
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Musculoskeletal Discomfort | 6 months and 12 months | Discomfort Survey (WDS) was used to assess symptoms and activity limitations. Participants reported on their work schedule, medication used for pain control, and discomfort in their neck/shoulder, back, and bilateral lower arms (elbows, forearms, wrists, and hands) using an 11-point numerical rating scale (0 = no discomfort/no limitations; 10 = unbearable discomfort/major limitations). We had to dichotomize the data during analysis due to severe skew towards not discomfort (0). Thus the final outcome was discomfort -yes or no |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Group A Subject receives typical keyboard first (0-6 months) and alternative keyboard second (7-12 months). In this crossover design all subjects received both standard and alternative keyboard, each group just received the keyboards in a different order | 40 |
| Group B Subject receives alternative keyboard first (0-6 months) and typical keyboard second (7-12 months). In this crossover design all subjects received both standard and alternative keyboard, each group just received the keyboards in a different order | 37 |
| Total | 77 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Period 1 | Lost to Follow-up | 2 | 0 |
| Period 1 | Withdrawal by Subject | 2 | 8 |
| Period 2 | Withdrawal by Subject | 2 | 1 |
Baseline characteristics
| Characteristic | Group B | Total | Group A |
|---|---|---|---|
| Age, Continuous | 45.6 years STANDARD_DEVIATION 11.9 | 44.4 years STANDARD_DEVIATION 12.4 | 43.3 years STANDARD_DEVIATION 12.9 |
| Avg Computer Use | 6.1 hrs/day STANDARD_DEVIATION 1.5 | 6.2 hrs/day STANDARD_DEVIATION 1.3 | 6.3 hrs/day STANDARD_DEVIATION 1.1 |
| Baseline Discomfort Back (Yes) | 33 participants | 66 participants | 33 participants |
| Baseline Discomfort Left Arm hand (Yes) | 24 participants | 46 participants | 22 participants |
| Baseline Discomfort Neck (Yes) | 36 participants | 72 participants | 36 participants |
| Baseline Discomfort Right arm hand (Yes) | 36 participants | 69 participants | 33 participants |
| Ethnicity (NIH/OMB) Hispanic or Latino | 0 Participants | 1 Participants | 1 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 37 Participants | 76 Participants | 39 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants | 1 Participants | 1 Participants |
| Race (NIH/OMB) Black or African American | 5 Participants | 8 Participants | 3 Participants |
| Race (NIH/OMB) More than one race | 1 Participants | 1 Participants | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) White | 31 Participants | 67 Participants | 36 Participants |
| Region of Enrollment United States | 37 participants | 77 participants | 40 participants |
| Sex: Female, Male Female | 35 Participants | 71 Participants | 36 Participants |
| Sex: Female, Male Male | 2 Participants | 6 Participants | 4 Participants |
| Typing Speed Don't know | 8 participants | 14 participants | 6 participants |
| Typing Speed Fast | 12 participants | 23 participants | 11 participants |
| Typing Speed Moderately Fast | 14 participants | 30 participants | 16 participants |
| Typing Speed Slow | 3 participants | 10 participants | 7 participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — |
| other Total, other adverse events | 0 / 85 | 0 / 85 |
| serious Total, serious adverse events | 0 / 85 | 0 / 85 |
Outcome results
Primary
Musculoskeletal Discomfort
Discomfort Survey (WDS) was used to assess symptoms and activity limitations. Participants reported on their work schedule, medication used for pain control, and discomfort in their neck/shoulder, back, and bilateral lower arms (elbows, forearms, wrists, and hands) using an 11-point numerical rating scale (0 = no discomfort/no limitations; 10 = unbearable discomfort/major limitations). We had to dichotomize the data during analysis due to severe skew towards not discomfort (0). Thus the final outcome was discomfort -yes or no
Time frame: 6 months and 12 months
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Typical Keyboard | Musculoskeletal Discomfort | 20 percentage of subjects with MSD |
| Alternative Keyboard | Musculoskeletal Discomfort | 20 percentage of subjects with MSD |
Comparison: Subjects were compared across keyboard types - The percentage of subjects with MSD when using the alternative keyboard were compared to the % of subjects with MSD when they were using the typical keyboardp-value: >0.05GEE