Acute non-contact anterior cruciate ligament tears are associated with relatively increased vastus medialis to semimembranosus cross-sectional area ratio: a case-control retrospective MR study

Abstract

Acute non-contact ACL tears are associated with increased VM:SM CSA ratios, which may imply a relative deficiency in hamstring strength. This study also demonstrates a novel method of measuring the relative CSA of muscles on MRI.

Effects of Different Combinations of Concentric and Eccentric Resistance Training Programs on Traditional and Alternative Hamstrings-to-Quadriceps Ratios

“…Since we only tested the nondominant leg, our results may be important for athletes from sports that require weight-bearing of the nondominant leg to support actions of the dominant leg, which may lead to greater risk of knee ligament injuries [2,22]. However, recent evidence has indicated that H:Q ratios calculated by PT alone may be weak indicators of future injury incidence in sports [8,39], and that this relationship may also be influenced by other neuromuscular variables, such as RTD, MS, MA, muscle fatigue, and torque produced at multiple angles of ROM [9,11,13,14,15,16,17,21,40,41]. Therefore, because of the multifactorial nature of hamstring strain ACL tears [8,42], increasing traditional and alternative H:Q ratios (based on more than one of these neuromuscular variables) have been proposed as potential strategies for enhancing performance and reducing injury risk [9].…”

“…MS increases have been thought to be a primary determinant of strength gains following resistance training [43]. Because of this relationship, a few studies have suggested that a reduced MS H:Q ratio can also indicate an increased knee strength imbalance and potential risk of injury [15,16,17]. For instance, Evangelidis et al [15] demonstrated that quadriceps MS explained about 30% to 31% of CON PT, and that hamstrings MS explained about 48% to 58% of ECC PT.…”

“…Additionally, since these traditional methods of calculating H:Q ratios only account for knee balance based on the maximum strength capacity (i.e., PT), recent investigations have proposed alternative methods of determining H:Q ratios that consider balance between other neuromuscular variables that can influence the antagonist to agonist muscle relationship. This is the case of H:Q ratios calculated by rate of torque development (RTD) [11,12,13,14], muscle size (MS) [15,16,17], and muscle activation (MA) [18,19]. Indeed, a recent review has suggested that the use of these alternative H:Q ratios combined with the traditional H:Q ratios calculated by PT may provide a more comprehensive assessment of an individual’s H:Q muscle balance and associated injury risk [9].…”

“…Previous studies have suggested that future longitudinal investigations should be performed to provide greater insight about the most appropriated resistance training program for reducing potential injury risk as indicated by increased traditional and alternative H:Q ratios [9,14,16]. However, to our knowledge, no study has investigated the effects of different resistance training programs on both traditional and alternative H:Q ratios.…”

Skeletal Radiology: The Year in Review 2017

“…Wieschhoff and colleagues [8] measured the cross-sectional areas of both the vastus medialis and the semimembranosus muscles on the highest available axial image of a conventional knee MRI. They demonstrated that in patients who sustained a non-contact tear of the ACL, the quadriceps (vastus medialis) was disproportionately large compared to the hamstring (semimembranosus).…”