Five weeks of whole-body vibration in prehabilitation for knee function following anterior cruciate ligament reconstruction: a single-blinded randomized controlled trial

<p dir="ltr"><b>Background:</b> Good preoperative quadriceps neuromuscular function is associated with satisfactory functional outcomes post-anterior cruciate ligament reconstruction (ACLR). Whole-body vibration (WBV), which can modulate quadriceps neuromuscular function has not yet been incorporated into ACL prehabilitation. The aim of this study was to determine whether the combination of WBV in a prehabilitation program could achieve a better knee function after ACLR by promoting quadriceps neuromuscular function during the preoperative period.</p><p dir="ltr"><b>Methods: </b>A single-blinded randomized controlled clinical trial was conducted. Forty-four participants with a primary, unilateral ACL rupture were randomly assigned to the control (<i>N</i> = 22) or the WBV group (<i>N</i> = 22). The control group underwent prehabilitation twice weekly for five weeks. The WBV group received the same prehabilitation plus WBV. Quadriceps neuromuscular function, including strength (maximal voluntary isometric contraction, MVIC), the early (rate of torque development from 0 to 50ms, RTD_{0 − 50}), and the late phase (rate of torque development from 100 to 200ms, RTD_{100 − 200}) of rapid contraction and inhibition (central activation ratio, CAR) in the injured limb, were measured at baseline and preoperatively. Knee function was assessed by the International Knee Documentation Committee (IKDC) Score at baseline, preoperatively, and 4 months postoperatively. The linear mixed effect models and multiple linear regression were used for the statistical analyses.</p><p dir="ltr"><b>Results:</b> Forty participants completed interventions and 35 finished the postoperative follow-up. Preoperatively, the intervention demonstrated main effects on quadriceps MVIC (<i>p</i> = 0.002), RTD_{0 − 50} (<i>p</i> = 0.024), RTD_{100 − 200} (<i>p</i> = 0.005) and CAR (p = 0.043). Furthermore, the effect of time* intervention interaction was significant on quadriceps MVIC (<i>p</i> = 0.011). Postoperatively, the WBV group achieved higher IKDC scores than the control group (<i>p</i> = 0.006). The improvements in preoperative quadriceps MVIC and intervention contributed to better knee function post-ACLR (R² = 0.239, <i>p</i> = 0.007).</p><p dir="ltr"><b>Conclusions:</b> Five weeks of WBV in prehabilitation enhanced quadriceps strength pre-ACLR and had potential to enhance knee function post-ACLR. WBV can be considered as an adjunct to prehabilitation protocols.</p>