Quadriceps rate of torque development and disability in individuals with anterior cruciate ligament reconstruction.

BACKGROUND: The purpose of this study was to determine associations between self-reported function (International Knee Documentation Committee Index), isometric quadriceps strength and rate of torque development in individuals with a unilateral anterior cruciate ligament reconstruction.

METHODS: Forty-one individuals [31% male, BMI mean 25 (SD 4) kg/m2 , months post anterior cruciate ligament reconstruction mean 49 (SD 40)] completed the self-reported function and isometric quadriceps function testing. Rate of torque development was assessed at 0-100ms (early), 100-200ms (late) ms, and peak following the onset of contraction. Associations were examined between rate of torque development, strength, and self-reported function. Linear regression was used to determine the unique amount of variance explained by the combination of rate of torque development and strength.

FINDINGS: Higher rate of torque development 100-200ms is weakly associated with higher self-reported function in individuals with a unilateral anterior cruciate ligament reconstruction (r=0.274, p=0.091); however, rate of torque development 100-200ms does not predict a significant amount of variance in self-reported function after accounting for strength (ΔR2 =0.003, P=0.721).

INTERPRETATION: Quadriceps strength has a greater influence on self-reported function compared to rate of torque development in individuals with an anterior cruciate ligament reconstruction with time from surgery.