The hamstrings are more impacted than the quadriceps after severe ankle sprain

Abstract

Ankle sprains (AS) are common in the military population, with a prevalence 5 to 8 times higher than that for civilians. The aim of this study was to evaluate in patients with severe AS the impact of disuse on thigh muscle induced by unloading and immobilization due to care. This study focused on muscle trophicity and dynamometric strength. In this observational prospective study, assessments were repeated at 3 visits: close to injury, 15 and 30 days following the sprain. The injured limb was compared to the contralateral limb. A dynamometer assessment was used to monitor changes in strength and fatigue of the thigh muscles of both limbs. Isometric and isokinetic concentric evaluation of peak torque (PTiso and PTdyn), total work (Wt), and peak torque time integral (IPT) of thigh muscles. Full follow-up was obtained in 30 subjects. The injured limbs showed significant deficits in the mean (SD). The quadriceps PTiso and IPT deficits were −12.6% ± 1.9% ( P < .0001) and −13.27% ± 1.8% ( P < .0001), respectively. The quadriceps PTdyn showed a significant deficit since V2 (−12.2.5% ± 2.0). The quadriceps Wt presented a significant deficit of −4.2% ± 2.4 ( P < .0007) at 1 month. The hamstring PTdyn deficit presented a mean loss of −16.5% ± 2.4% ( P < .0001). The hamstring Wt deficit was −13.7% ± 2.3% ( P < .001). The analysis of variance showed that the grade of the sprain had a significant effect on the quadriceps PTq deficit ( P < .016) but not the type of discharge. Our study showed that disuse leads to a significant deficit in the strength of knee muscles within 1 month. It is noteworthy that the hamstrings are more affected than the quadriceps. The rehabilitation protocol to prevent the risk of iterative ankle injuries and secondary knee injuries should incorporate early training of both quadriceps and hamstrings.

Individuals With Chronic Ankle Instability Show Abnormalities in Maximal and Submaximal Isometric Strength of the Knee Extensor and Flexor Muscles

“…Previous studies assessing quadriceps muscle strength have reported contrasting results. 13 , 23 , 41 The contrasting results may be related to heterogeneity in strength-testing methodology as well as characteristics of the study sample. Thus, further research is needed to clarify this point.…”

“… 19 , 21 The quadriceps facilitation in turn, as a consequence of the antagonist inhibition phenomenon, leads to hamstring inhibition. In addition, it has been shown that a marked decrease in hamstring muscle strength can be seen early after a severe ankle sprain, 13 as well as in individuals with chronic instability of the ankle. 45 Taken together, these results suggest that a likely immediate reflex inhibition is seen in the muscles directly acting on the ankle and that, at the same time or as a longer-term adaptation, inhibition and facilitation mechanisms arise in muscles acting on more proximal joints.…”

“… 22 , 29 , 33 Although many studies have investigated abnormalities in muscle strength and activation of muscles around the ankle joint, 5 , 6 , 8 , 10 , 31 , 34 , 52 and more recent studies are reporting abnormalities related to the hip muscles, 1 ,29, 34 , 38 , 39 contrasting evidence has been provided for muscles acting on the knee. 12 , 13 , 23 , 41 , 45 , 51 Studies assessing knee extensor and flexor isokinetic muscle strength reported either lower muscle strength of knee extensor and flexor muscles 12 , 13 , 23 or no differences in muscle strength 41 when compared with healthy controls. Furthermore, contrasting results also arise from studies focusing on mechanisms related to neural and mechanical muscle function.…”