Rate of Force Development Remains Reduced in the Knee Flexors 3 to 9 Months After Anterior Cruciate Ligament Reconstruction Using Medial Hamstring Autografts: A Cross-Sectional Study

Abstract

Background: Anterior cruciate ligament (ACL) rupture is a serious injury with a high prevalence worldwide, and subsequent ACL reconstructions (ACLR) appear to be most commonly performed using hamstring-derived (semitendinosus tendon) autografts. Recovery of maximal muscle strength to ≥90% of the healthy contralateral limb is considered an important criterion for safe return to sports. However, the speed of developing muscular force (ie, the rate of force development [RFD]) is also important for the performance of many types of activities in sports and daily living, yet RFD of the knee extensor and flexor muscles has apparently never been examined in patients who undergo ACLR with hamstring autograft (HA). Purpose: To examine potential deficits in RFD, maximal muscle strength (ie, maximal voluntary isometric contraction [MVIC]), and functional capacity of ACLR-HA limbs in comparison with the healthy contralateral leg and matched healthy controls 3 to 9 months after surgery. Study Design: Cross-sectional study; Level of evidence: 3. Methods: A total of 23 young patients who had undergone ACLR-HA 3 to 9 months earlier were matched by age to 14 healthy controls; both groups underwent neuromuscular screening. Knee extensor and flexor MVIC and RFD, as well as functional capacity (single-leg hop for distance [SLHD] test, timed single-leg sit-to-stand [STS] test), were assessed on both limbs. Furthermore, patient-reported knee function (Knee injury and Osteoarthritis Outcome Score) was assessed. Results: Knee extensor and flexor MVIC and RFD were markedly compromised in ACLR-HA limbs compared with healthy contralateral limbs (MVIC for extensor and flexor, 13% and 26%, respectively; RFD, 14%-17% and 32%-39%) and controls (MVIC, 16% and 31%; RFD, 14%-19% and 30%-41%) ( P < .05-.001). Further, ACLR-HA limbs showed reduced functional capacity (reduced SLHD and STS performance) compared with contralateral limbs (SLHD, 11%; STS, 14%) and controls (SLHD, 20%; STS, 31%) ( P < .01-.001). Strength (MVIC) and functional (SLHD) parameters were positively related to the duration of time after surgery ( P < .05), although this relationship was not observed for RFD and STS. Conclusion: Knee extensor and flexor RFD and maximal strength, as well as functional single-leg performance, remained substantially reduced in ACLR-HA limbs compared with noninjured contralateral limbs and healthy controls 3 to 9 months after reconstructive surgery.

Explosive hamstrings strength asymmetry persists despite maximal hamstring strength recovery following anterior cruciate ligament reconstruction using hamstring tendon autografts

“…Analysis of the effects of sex on maximal and explosive strength following ACLR showed that males and females are typically affected similarly in the hamstrings but not in the quadriceps. This is in contrast to the results by Nielsen et al [ 30 ] who found significant effects of sex (female more impacted than males) in maximal and explosive hamstrings strength between 3 and 9 months following ACLR. An explanation for these differences could be the larger sample size, longer duration and the frequency and timing of testing throughout ACL rehabilitation (comparing early and late rehabilitation) in this study compared to their study.…”

“…Based on the results of this study, patients who had ACLR with HT autografts would show maximal hamstrings strength recovery (≥ 90% LSI) during late rehabilitation period even while still having significant explosive hamstring strength asymmetry. Previous studies have also found explosive hamstring strength deficits between 3–9 months [ 30 ] and 9–12 months [ 31 ] following ACLR. However, these results were taken from only one assessment time point.…”

Maximal vs. explosive knee extensor strength in professional soccer players: inter‐limb asymmetries and relationship with knee function

“…(Lehance et al, 2008) However, it has recently been suggested that explosive strength, i.e. the capacity to produce force/torque quickly during an explosive maximal voluntary contraction (MVC), is more representative of athletic performance as well as injury susceptibility (Padua et al, 2018; Suchomel et al, 2018; Zebis et al, 2011) and recovery (Jordan, Aagaard, & Herzog, 2015; Nielsen et al, 2020) than pure maximal strength. (Buckthorpe & Roi, 2017; Maffiuletti et al, 2016) Nowadays, the main index of explosive strength is represented by the rate of torque development (RTD), which is generally calculated as the slope of the torque‐time curve in distinct time intervals from contraction onset.…”

Wearables-Only Analysis of Muscle and Joint Mechanics: An EMG-Driven Approach

“…Muscle power, for example, is a well-known determinant of physical function [11] and the phenomena of work- [12] and load- [13] induced muscle hypertrophy motivate tracking cumulative muscle work and force which may provide a basis for optimal exercise prescription and understanding subsequent dose-response relationships [14]. These analyses may be especially relevant for monitoring patients post-ACLR wherein the knee extensor and flexor musculature are compromised [15], [16] due to muscle atrophy [17] and muscle activation deficits [15]. In this case, early intervention is critical [18] and continuous, remote monitoring augments personalized rehabilitation for targeting specific biomechanical outcomes [19].…”

“…The copyright holder for this preprint this version posted June 17, 2021. ; https://doi.org/10.1101/2021.06. 16.448524 doi: bioRxiv preprint (which was not certified by peer review) is the author/funder. All rights reserved.…”