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.

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

GEE analyses allows a subjects inclusion even if they did not complete the full trial. Although we had a total of 15 subjects not complete the full trial we had sufficient data on 77 subjects to complete the GEE statistical analyses. With the crossover design we compared 77 subjects using the standard keyboard to 77 subjects using the alternative