Forces transmitted along human flexor tendons during passive and active movements of the fingers.

The in vivo forces in human digital flexor tendons were determined in 33 patients undergoing a carpal tunnel decompression surgery using a newly developed device. The tendons were tested in passive and active flexion, and flexing against resistance of up to 500 g. Forces in the range of 0.2 to 50 N were noted. Whilst the mean of these forces remained below the force normally required to dehisce a fresh modified Kessler repair, the range of values was such that we would only recommend early movement with great caution and under supervision.