Agreement of three vs. eight Isokinetic preset velocities to determine knee extensor torque and power-velocity relationships

摘要

BACKGROUND: Torque and power-velocity relationships obtained during isokinetic evaluation can be useful for rehabilitation program. Nevertheless, their determination requires a substantial number of measures using different velocities, inducing time-consuming protocols.OBJECTIVE: The aim of the present study was to assess the agreement between a short isokinetic protocol, including three angular velocities (P3) and a longer one including eight angular velocities (Ps).METHODS: Sixteen healthy male subjects performed isokinetic knee extensions at several preset velocities during two protocols. The first included eight velocities ranging from 60 to 270°/s (Ps), whereas the second (P3) consisted of three velocities (90, 180 and 240°/s). Mechanical parameters: theoretical maximal isometric torque To, theoretical maximal velocity Vb, and maximal power Pmax, were extrapolated from torque- and power-velocity relationships for both P_8 and P_3.RESULTS: The torque- and power velocity relationships drawn from each protocol were in agreement since no significant differences were found for either each extrapolated mechanical parameters, between the slopes of the torque-velocity relationships, or between the polynomial regression coefficients of the power-velocity relationships resulting from P_8 and P_3. CONCLUSION: The agreement between the short and long protocols allows reduction of fatigue and loss of motivation that may occur during full velocities testing particularly during rehabilitation program.