Biomechanical Profiles When Towing a Sled and Wearing a Weighted Vest Once Cleared for Sports Post–ACL Reconstruction

Abstract

Background:Though rehabilitation attempts to correct “stiff knee gait” and control for dynamic limb valgus after anterior cruciate ligament reconstruction (ACLR), impaired biomechanics often persist when an individual is cleared to return to sport (RTS). Reduced knee extension moments (KEMs) and knee flexion angles (KFAs) often continue. While at the hip, increased hip adduction angles (HADDAs) and hip internal rotation angles (HIRAs) often persist in spite of dynamic hip stabilization exercises. Sled towing and weighted vest tasks increase KEM and hip extension moments (HEMs) in healthy individuals, yet biomechanical profiles during these tasks after ACLR are unknown.Hypothesis:Weighted gait will increase KEM, HEM, hip abduction moments (HABDMs), and hip external rotation moments (HERMs) and will not increase unwanted biomechanics (limb asymmetries, HIRA, HADDA) compared with normal gait.Study Design:Controlled laboratory study.Level of Evidence:Level 4.Methods:Fourteen men and 24 women who were 5 to 12 months after ACLR, had no concomitant ligament injuries, and were cleared to RTS were recruited. Sexes were evaluated independently given the sex-specific incidence to ACL injury, reinjury, and gait responses to certain interventions. Joint moment impulses and peak angles over the first 25% of stance were compared between limbs and across tasks (eg, unweighted gait, sled 50% body weight [BW], and vest 50% BW).Results:Men showed that weighted gait increased KEM, HEM, HERM, HADBM (vest only), HADDA, HIRA (sled only), and KFA. Asymmetrical KEM and KFA existed across tasks. Women showed that weighted gait increased KEM, HEM, HERM, HADBM (vest only), HFA (sled only), HADDA, and KFA. Asymmetrical KEM, HEM, HIRA, and KFA (sled only) existed across tasks.Conclusion:Weighted gait generally increased joint moments. Unwanted biomechanics were unique for each weighted gait task.Clinical Relevance:Though joint moments increased, both tasks created unwanted biomechanics after ACLR. Persistent hip (women only) and KEM asymmetries across tasks when cleared to RTS are concerning given the relationship among these biomechanics and decreased functional performance.

Report of the Primary Outcomes for Gait Mechanics in Men of the ACL-SPORTS Trial: Secondary Prevention With and Without Perturbation Training Does Not Restore Gait Symmetry in Men 1 or 2 Years After ACL Reconstruction

“…The present study corroborates these findings and underscores that limb asymmetries remain present 2 years postoperatively even among individuals who are well rehabilitated after ACLR and have returned to sports [1]. The present study adds to a growing body of rehabilitation paradigms that have not succeeded in restoring gait symmetry [10,21,35]. Notably, gait asymmetries (including smaller INV versus UN limb knee flexion angles) persisted among patients after ACLR even when towing a sled or wearing a weighted vest [21].…”

“…The present study adds to a growing body of rehabilitation paradigms that have not succeeded in restoring gait symmetry [10,21,35]. Notably, gait asymmetries (including smaller INV versus UN limb knee flexion angles) persisted among patients after ACLR even when towing a sled or wearing a weighted vest [21]. Interestingly, previous studies have typically evaluated gait mechanics in the short and medium term by comparing group means rather than the proportion of individuals who walk with clinically meaningful asymmetries, as was done in the present study.…”

Gait Mechanics in Women of the ACL‐SPORTS Randomized Control Trial: Interlimb Symmetry Improves Over Time Regardless of Treatment Group

“…The early phases of rehabilitation are focused almost exclusively on the involved, surgical limb, but during the 10 post‐operative return‐to‐sport training sessions, participants begin doing higher level activities on both limbs for the first time after surgery. During this return‐to‐sport training, participants may develop movement strategies that rely more heavily on the uninvolved limb, favoring the involved limb due to lingering deficits or lack of confidence …”

<strong>Determination of Risk Factors Associated With Walking Disorders After Anterior Cruciate Ligament Surgery With Hamstring Graft : A Controlled Multicenter Study </strong>

“…All these changes that occur in the walking pattern are not found in a healthy population whose BMI does not reflect overweight or obesity. Analysis studies of walking with weighted vests simulating overweight were carried out by Hartigan et al (27,28) respectively in 2017 and 2016, this time on operated patients.…”

“…One possible interpretation of these results would be that people tend to walk more cautiously to avoid the risk of falling and, as a result, neglect the coordination between gait and upper trunk when walking on the treadmill. Indeed, in many studies carried out in the literature, the analysis of walking is done on the ground (12,15) or on a force platform (13,27,28) , over a given distance (15) or not and at a speed determined by the subject (12,13,15,27,28) .…”