Lower extremity neuromuscular recovery following anterior cruciate ligament reconstruction; a 2-week case study

The lower extremity neuromuscular recovery of a 31-year-old male physical therapy student during the initial 2-weeks following anterior cruciate ligament reconstruction was evaluated by measuring involved side vastus medialis (VM), gluteus maximus (GMAX) and gastrocnemius (GASTROC) electromyographic (EMG) signals (1000 Hz), plantar forces (50 Hz), and knee pain as the subject performed a series of volitional, maximal effort unilateral, isometric leg presses (6 sec) in a modified continuous passive motion device. Data were standardized to pre-operative values and graphically plotted for split middle technique, celeration line assessment. From 1-8 hours post-surgery, EMG amplitudes and plantar forces decreased, pain increased, and plantar force location shifted toward the forefoot. From 9-12 hours post-surgery, EMG amplitudes and plantar forces increased and pain decreased. By 24 hours post-surgery, pain decreased to pre-operative levels. From 24-72 hours post-surgery, EMG amplitudes and plantar forces increased. From 1-2 weeks post-surgery, EMG amplitudes and plantar forces increased. From 9 hours-2 weeks post-surgery, plantar force location shifted toward the pre-operative location. Sequential increases were observed for GMAX, GASTROC, and VM EMG amplitudes. By 2 weeks post-surgery, plantar forces and VM EMG amplitudes remained reduced. Reduced plantar forces and VM EMG amplitude at 2 weeks post-surgery suggest a need for greater focus on restoring VM function before attempting closed kinetic chain exercises that require the full shock absorption capabilities of the quadriceps femoris muscle group.