Functional evaluation of intraarticular severely comminuted fractures of the calcaneus with gait analysis.

Twenty-one patients (23 feet) treated nonsurgically for severely comminuted intraarticular fractures of the calcaneus were evaluated prospectively with a clinical scoring scale and computerized gait analysis. All patients had Sanders type III and type IV fractures. The treatment protocol consisted of no closed reduction, immobilization in removable splint, physiotherapy after edema subsided, and weightbearing after 8 weeks. All patients had a minimum follow-up of 2 years (mean, 38 months). Clinical results were good in 2 patients, fair in 3 patients, and poor in 16 patients. Gait analysis showed that patients were at high risk of gastrocnemius weakness and ankle and knee instability. These results may be useful for comparison with the results of other methods, such as open reduction and internal fixation, nonsurgical closed reduction, and arthrodesis.

Activation patterns in forearm muscles during archery shooting.

A contraction and relaxation strategy with regard to forearm muscles during the release of the bowstring has often been observed during archery, but has not well been described. The purpose of this study was to analyze this strategy in archers with different levels of expertise; elite, beginner and non-archers. Electromyography (EMG) activity of the M. flexor digitorum superficialis and the M. extensor digitorum were recorded at a sampling frequency of 500 Hz, together with a pulse synchronized with the clicker snap, for twelve shots by each subject. Raw EMG records, 1-s before and after the clicker pulse, were rectified, integrated and normalized. The data was then averaged for successive shots of each subject and later for each group. All subjects including non-archers developed an active contraction of the M. extensor digitorum and a gradual relaxation of the M. flexor digitorum superficialis with the fall of the clicker. In elite archers release started about 100 ms after the fall of the clicker, whereas in beginners and non-archers release started after about 200 and 300 ms, respectively. Non-archers displayed a preparation phase involving extensive extensor activity before the release of the bowstring, which was not observed in elite and beginner archers. In conclusion, archers released the bowstring by active contraction of the forearm extensors, whereas a clear relaxation of the forearm flexors affecting the release movement was not observed.