Self-release of ski-binding.

We investigated whether twenty-five male and female downhill skiers of different ages (11 - 63 years) and skiing skills were able to self-release their ski binding by an inward twist of the foot and leg. We also studied possible correlations between thigh muscle torques and the ability to release the binding. All subjects used the same ski and binding, Marker Titanum M48, individually set according to weight, height, skiing skill, age, and boot sole length. Prior to the test we used a special torque wrench, the Vermont Release Calibrator, to verify that the settings of the binding corresponded to the appropriate torque (Nm) to produce a release. Isokinetic concentric and eccentric quadriceps and hamstring torques were measured. EMG was used to study which muscles are engaged in this self-test. Nineteen skiers were able to release the binding, while four children and the two muscularly weakest skiers were not. The medial hamstrings produced the highest degree of muscle activity during the inward twist release of the binding. There was a highly significant correlation between thigh muscle torques and the ability to release the binding.