Measuring force transfers in the deep flexors of the musician's hand: theoretical analysis, clinical examples.

In the present paper the anatomical and functional interdependencies which regularly exist between the deep flexor tendons of the different fingers are modelled. The model results are validated by measurements on real hands. The results show that intertendinous force transfers may be caused by (i) coactivation of muscle fibres inserting in different tendons, and (ii) passive connections between tendons or muscle bellies. The coactivation is validated by the measuring results of a hand in which all intertendinous connections were surgically removed. The present models and measurements are currently used for diagnosis of hand problems in musicians at our hand clinic.