Background: An objective test is needed to evaluate outcome following carpal tunnel release. A method to evaluate sensory and motor function related to carpal tunnel syndrome was investigated.

Methods: Thirty-six candidates for carpal tunnel surgical procedures underwent a physical examination and nerve-conduction studies and completed a survey regarding symptoms. A battery of psychomotor and sensory tests was administered bilaterally immediately before surgery and again six weeks after surgery. The outcome variables included dynamic sensory gap-detection thresholds and rapid pinch-and-release rates.

Results: The average gap-detection threshold for the index finger in the surgical-treatment group demonstrated a 43% improvement, decreasing from 0.14 mm preoperatively to 0.08 mm at six weeks postoperatively (p < 0.01). The average gap-detection threshold for the index finger in the non-surgical-treatment group demonstrated no significant improvement, decreasing from 0.10 mm preoperatively to 0.08 mm postoperatively (p = 0.10). With the upper force level set at 10% of the maximum voluntary contraction, the average pinch rate in the surgical-treatment group demonstrated a 20% improvement, increasing from 6.65 pinches per second preoperatively to 7.96 pinches per second postoperatively (p < 0.001). The average pinch rate in the non-surgical-treatment group demonstrated a 7% improvement, increasing from 6.89 pinches per second preoperatively to 7.37 pinches per second at six weeks postoperatively (p < 0.05).

Conclusions: Measurable and significantly greater improvement was observed when the surgical-treatment group was compared with the non-surgical-treatment group in terms of these two sensory and psychomotor functional testing outcomes at six weeks.

Level of Evidence: Therapeutic study, Level II-1 (prospective cohort study). See Instructions to Authors for a complete description of levels of evidence.