Forces Transmitted Along Human Flexor Tendons – The Effect of Extending the Fingers Against the Resistance Provided by Rubber Bands

We wished to test the hypothesis that postoperative extension of repaired flexor tendons against rubber bands will reduce the stress on the repairs, and therefore the risk of rupture. During 24 routine carpal tunnel decompression operations the force in flexor tendons was measured using a load cell. The patients flexed and extended their fingers with and without a rubber band providing resistance to extension. We found no statistically significant difference between the force measured in the tendon with or without the presence of rubber bands. To conclude, we have shown that if the application of rubber band dynamic splintage after flexor tendon repair has any advantage, it is not by reducing the forces transmitted along the tendon during resisted extension or by aiding flexion.