Neuromuscular and psychological characteristics in subjects with work-related forearm pain

There are scant data available on the neuromuscular and psychological chara cteristics of patients with cumulative trauma disorders. We compared 16 sub jects with work-related forearm and hand pain in the dominant upper limb wi th 9 age-matched control subjects. Pain subjects were divided into two grou ps based on nerve conduction studies: eight subjects were in the study grou p for median neuropathy at the wrist (MN, median transcarpal latency >2.3 m s), and eight were in the study group for electrodiagnostically negative pa in (EN). Average pain, forearm muscle tenderness, grip strength, pinch stre ngth, and wrist flexor and extensor strength were measured. The Health Stat us Questionnaire and the Beck Depression Inventory were used to measure hea lth perception and depressive symptoms, respectively. Work satisfaction was determined by a newly devised scale. Statistical analysis was by analysis of variance and planned comparison analysis. The MN and EN groups did not s ignificantly differ on any of the measures except median transcarpal latenc y. Both pain groups had significantly (P < 0.05) greater average pain, grea ter extensor muscle tenderness, higher Beck Depression Inventory scores, hi gher pain rating, and poorer physical functioning on the Health Status Ques tionnaire than did the normal control group. Grip strength and wrist extens ion force were diminished in both cumulative trauma groups compared with co ntrol subjects; however, only grip strength in the MN group and wrist exten sion force in the EN group differed significantly (P < 0.05) from control s ubjects. Only the EN group had significantly less work satisfaction than di d the control group. Overall, both pain groups differed from control subjec ts and shared similar characteristics, with the exception of median neuropa thy.