Quadriceps neural alterations in anterior cruciate ligament reconstructed patients: A 6-month longitudinal investigation.
The purpose of this investigation was to evaluate differences in quadriceps corticospinal excitability, spinal-reflexive excitability, strength, and voluntary activation before, 2 weeks post and 6 months post-anterior cruciate ligament reconstruction (ACLr). This longitudinal, case-control investigation examined 20 patients scheduled for ACLr (11 females, 9 males; age: 20.9 ± 4.4 years; height:172.4 ± 7.5 cm; weight:76.2 ± 11.8 kg) and 20 healthy controls (11 females, 9 males; age:21.7 ± 3.7 years; height: 173.7 ± 9.9 cm; weight: 76.1 ± 19.7 kg). Maximal voluntary isometric contractions (MVIC), central activation ratio (CAR), normalized Hoffmann spinal reflexes, active motor threshold (AMT), and normalized motor-evoked potential (MEP) amplitudes at 120% of AMT were measured in the quadriceps muscle at the specific time points. ACLr patients demonstrated bilateral reductions in spinal-reflexive excitability compared with controls before surgery (P = 0.02) and 2 weeks post-surgery (P ≤ 0.001). ACLr patients demonstrated higher AMT at 6 months post-surgery (P ≤ 0.001) in both limbs. No MEP differences were detected. Quadriceps MVIC and CAR were lower in both limbs of the ACLr group before surgery and 6 months post-surgery (P ≤ 0.05) compared with controls. Diminished excitability of spinal-reflexive and corticospinal pathways are present at different times following ACLr and occur in combination with clinical deficits in quadriceps strength and activation. Early rehabilitation strategies targeting spinal-reflexive excitability may help improve postoperative outcomes, while later-stage rehabilitation may benefit from therapeutic techniques aimed at improving corticospinal excitability.
['Lepley|A S|AS|', 'Gribble|P A|PA|', 'Thomas|A C|AC|', 'Tevald|M A|MA|', 'Sohn|D H|DH|', 'Pietrosimone|B G|BG|']
D000293:Adolescent D000328:Adult D059549:Anterior Cruciate Ligament Reconstruction D016022:Case-Control Studies D004576:Electromyography D019054:Evoked Potentials, Motor D005260:Female D006801:Humans D007537:Isometric Contraction D008137:Longitudinal Studies D008297:Male D053580:Muscle Strength D011712:Pyramidal Tracts D052097:Quadriceps Muscle D012021:Reflex, Abnormal D050781:Transcranial Magnetic Stimulation D055815:Young Adult
Knee injury muscle inhibition neuromuscular function transcranial magnetic stimulation