Hoffmann reflex profiles and strength ratios in postoperative anterior cruciate ligament reconstruction patients

Rupture of the anterior cruciate ligament (ACL) typically leads to surgical reconstruction followed by an extensive rehabilitation program. One of the most commonly experienced complications associated with ACL rupture and reconstruction is quadriceps muscle atrophy. A clear understanding of the exact mechanisms associated with ACL related atrophy remains undocumented. The purpose of the present study was to investigate maximum H-reflex to maximum M-wave ratio as well as quadriceps deficit for both isometric and isokinetic peak torques in a post ACL reconstruction population. Forty subjects volunteered for participation in this study. The experimental group comprised 20 subjects who had undergone patellar tendon graft reconstruction of a torn ACL. A matched control group of 20 subjects were also measured for comparative purposes. The results indicated the control group had significantly higher quadriceps to quadriceps ratio than did the ACL group [t(38) = 9.05 p < .001]. In contrast, there was no difference in the H-max/M-max ratio for either group or leg. The strength findings of this study support previous findings. The spinal reflex results support the need for additional research in this area, specifically with more acutely injured subjects.