Acute changes in hamstrings musculo-articular dissipative properties induced by cyclic and static stretching

Antoine Nordez (1) , P. Mc Nair (2) , Pascal Casari (3) , C. Cornu (1)

1 MIP - Motricité, interactions, performance EA 4334 / Movement - Interactions - Performance
2 Physical Rehabilitation Research Centre
3 GeM - Institut de Recherche en Génie Civil et Mécanique

This study was designed to measure changes in musculo-articular dissipative properties related to viscosity that were induced by passive cyclic and static stretching. Musculo-articular dissipative properties were assessed by calculating a dissipation coefficient using potential elastic energies stored and restituted during cyclic stretching. Eight subjects performed five passive knee extensions/flexions cycles on a Biodex dynamometer at 5 degrees/s to 80 % of their maximal range of motion before and after a static stretching protocol. Electromyographic activity from the hamstring muscles was monitored and remained constant during cyclic stretching and after static stretching (p > 0.05). The dissipation coefficient decreased during cyclic stretching (- 28.8 +/- 6.0 %, p < 0.001), while it was slightly increased after static stretching (+ 3.8 +/- 5.0 %, p = 0.037). The findings showed that energy stored and energy restituted decreased during cyclic stretching and after static stretching (p < 0.05). During unloading, passive torque remained constant during cyclic stretching, but was decreased after static stretching. The findings indicate that musculo-articular dissipative properties were primarily affected by a single cycle of motion, and were not influenced by static stretching procedures. The decrease in dissipation coefficient following cyclic motion indicates that the musculo-articular system displays thixotropic behavior.

Mots clés: potential elastic energy; hysteresis; passive torque; viscosity; thixotropy

Domaines: Biomécanique [physics.med-ph]

Antoine Nordez, P. Mc Nair, Pascal Casari, C. Cornu. Acute changes in hamstrings musculo-articular dissipative properties induced by cyclic and static stretching. International Journal of Sports Medicine, 2008, 29 (5), pp.414-422. ⟨10.1055/s-2007-964980⟩. ⟨hal-01004977⟩