Isokinetic muscle strength and readiness to return to sport following anterior cruciate ligament reconstruction: is there an association? A systematic review and a protocol recommendation

The aim of the study was to describe objective and self-reported knee function for athletes who have returned to elite handball and football play after an ACL injury, comparing these to non-injured players at the same level. A total of 414 handball and 444 football players completed baseline tests from 2007 through 2014, examining lower extremity strength, dynamic balance, knee laxity, and knee function (KOOS questionnaire). Measures were compared between injured and non-injured legs and between injured legs and legs of controls. Eighty (9.3%) of the 858 players reported a previous ACL injury, 1-6 years post-injury (3.5±2.5 years), 49 handball (61.3%) and 31 football players (38.7%). We found no difference in strength or dynamic balance between previously ACL-injured (N=80) and non-injured players legs (N=1556). However, lower quadriceps (6.3%, 95% CI: 3.2-9.2) and hamstrings muscle strength (6.1%, 95% CI: 3.3-8.1) were observed in previously ACL-injured legs compared to the non-injured contralateral side (N=80). ACL-injured knees displayed greater joint laxity than the contralateral knee (N=80, 17%, 95% CI: 8-26) and healthy knees (N=1556, 23%, 95% CI: 14-33). KOOS scores were significantly lower for injured knees compared to knees of non-injured players. ACL-injured players who have successfully returned to elite sport have comparable strength and balance measures as their non-injured teammates. Subjective perception of knee function is strongly affected by injury history, with clinically relevant lower scores for the KOOS subscores Pain, Function, Sport, and Quality Of Life.

Section: Discussionmentioning

confidence: 99%

“…Nevertheless, it is considered as the “gold standard” for measuring muscle strength . Our isokinetic strength protocol with concentric tests at 60°/s is proposed as the most valid assessment for return to sport in a recent review …”

Section: Discussionmentioning

confidence: 99%

Knee function among elite handball and football players 1‐6 years after anterior cruciate ligament injury

Myklebust

Bahr

Nilstad

et al. 2017

“…After a 10 minutes break following completion of laboratory testing, concentric knee extensor and flexor strength were measured using an isokinetic dynamometer (Cybex Humac NORM, CSMI). All testing sessions were completed following protocol recommendations to assess isokinetic strength after ACLR . Participants were set up in a seated position, with stabilization belts placed across the thigh and shank on the tested limb.…”

Section: Methodsmentioning

confidence: 99%

Patellar and hamstring autografts are associated with different jump task loading asymmetries after ACL reconstruction

Miles

King

Falvey

et al. 2019

Self Cite

After anterior cruciate ligament reconstruction (ACLR), there is a higher re‐injury rate to the contralateral limb in athletes who undergo surgery using a bone‐patellar‐tendon‐bone (BPTB) autograft than using a semitendinosus and gracilis hamstring tendon (HT) autograft. This may be influenced by differing lower‐limb loading asymmetries present when athletes of each graft type return to play (RTP). The aim of this study was to compare bilateral countermovement jump (CMJ) phase‐specific impulse asymmetries between athletes with BPTB and HT autografts 9 months post‐ACLR, and to identify the relationship between impulse and isokinetic strength asymmetries. Male field sport athletes with a BPTB (n = 22) or HT (n = 22) autograft were tested approximately 9 months post‐ACLR. An uninjured control group (n = 22) was also tested on a single occasion. Phase‐specific bilateral absolute impulse asymmetries were calculated during the CMJ and compared between groups using Kruskal‐Wallis and post‐hoc testing. A linear regression model was used to assess the relationship between impulse asymmetries and isokinetic concentric knee extensor strength asymmetries. BPTB athletes demonstrated greater impulse asymmetries than HT athletes during the eccentric (P = 0.01) and concentric (P = 0.008) phases of the jump. Isokinetic strength asymmetry was a significant predictor of CMJ concentric impulse asymmetry in both BPTB (r2 = 0.39) and HT athletes (r2 = 0.18) but not eccentric impulse asymmetry in any group. The greater loading asymmetries demonstrated by BPTB than HT athletes 9 months after ACLR may contribute to the differing incidence rates of contralateral ACL injury. The findings suggest that graft‐specific loading asymmetries should be targeted during rehabilitation prior to RTP.

“…A meta‐analysis of the studies was not possible due to the limited reporting of values and data for any one biomechanical measure. A qualitative analysis was therefore implemented to provide a best‐evidence synthesis, and where possible, a subgroup analysis between studies was performed . Where one study utilized various methodological approaches (e.g.…”

Section: Methodsmentioning

confidence: 99%

Does the amount of lower extremity movement variability differ between injured and uninjured populations? A systematic review

Baida

Gore

Franklyn-Miller

et al. 2018

Movement variability during repetitive performance of a dynamic activity (eg, running, jumping, kicking) is considered an integral characteristic of optimal movement execution; however, its relationship with musculo-skeletal injury is not known. The primary aim of this study was to review published comparison trials to determine whether movement variability differs between uninjured controls and subjects with a lower limb musculo-skeletal injury. A systematic search of online databases; MEDLINE, Sports Discus, Scopus, and Web of Science was conducted from July to November 2016. Studies were selected if they (a) included participants with a lower limb injury, (b) compared injured participants to uninjured controls, (c) examined movement variability for at least one dependent variable, and (d) provided a statistical between-group comparison when comparing measures of movement variability. Studies were excluded if they (a) investigated neurological disorders, (b) examined musculo-skeletal injury in the upper extremity or spine, and (c) used nonlinear measures to examine variability (ie, complexity). A significant difference between injured and uninjured populations was reported in 73% of the included studies, and of these, 64% reported greater movement variability in the injured group. This is the first systematic review with a best-evidence synthesis investigating the association between movement variability and musculo-skeletal injury. Findings suggest that movement variability in those with a musculo-skeletal injury differs from uninjured individuals. Interestingly, there was an overall trend toward greater movement variability being associated with the injured groups, although it should be noted that this trend was not consistent across all subcategories (eg, injury type). For a clearer insight into the clinical application of variability, greater methodological homogeneity is required and prospective research is recommended.