Relationships of hamstring muscle volumes to lateral tibial slope

Background: Greater posterior-inferior directed slope of the lateral tibial plateau (LTS) has been demonstrated to be a prospective ACL injury risk factor. Trainable measures to overcome a greater LTS need to be identified for optimizing injury prevention protocols. It was hypothesized that Healthy individuals with greater LTS who have not sustained an ACL injury would have a larger lateral hamstring volume. Methods: Eleven healthy females (mean +/- standard deviation) (1.63 +/- 0.07 m, 62.0 +/- 8.9 kg, 22.6 +/- 2.9 years) & 10 healthy males (1.80 +/- 0.08 m, 82.3 +/- 12.0 kg, 23.2 +/- 3.4 years) underwent magnetic resonance imaging of the left knee and thigh. LTS, semitendinosus muscle volume, and biceps femoris long head muscle volume were obtained from imaging data. Results: After controlling for potential sex confounds (R-2 = .00; P = .862), lesser semitendinosus volume and greater biceps femoris-long head volume were indicative of greater LTS (R-2 Delta = .30, P = .008). Conclusions: Healthy individuals with greater LTS have a muscular morphologic profile that includes a larger biceps femoris-long head volume. This may be indicative of a biomechanical strategy that relies more heavily on force generation of the lateral hamstring and is less reliant on force generation of the medial hamstring. Level of evidence: Level IV. (C) 2017 Elsevier B.V. All rights reserved.