Muscle Injury

Direct Anterior Approach (DAA) is known to cause damage to the TFL during the surgical approach, the point of this study is to evaluate the impact between the severity of the per operative TFL damage and the functional short term results.

The study is a 2-week human study where 40 patients who are scheduled to undergo reconstructive knee surgery are randomized to administration of GH or placebo following or without neuromuscular electrical stimulation of hamstring muscles.The overall aim is to determine, the role of muscle connective tissue protein synthesis in muscle injury and repair.

Residual limping after total hip arthroplasty is empirically associated with the use of lateral approach but has been reported in litterature even with the use of posterior approach. The purpose of this clinical trial is to compare the risk of residual limping one year after total hip arthropasty between lateral and posterior approach.

There is in humans, at the muscular level, a great interindividual variability in response to the same mechanical stress. This phenotypic variability is multifactorial, influenced by environmental factors as well as multiple genetic variants. Thus, for the same level of muscle damage, two subjects with the same anthropometric characteristic, the same age, with the same medical history and the same level of physical activity, will present a variable level of muscle regeneration underpinned by the biological function of muscular stem cells and their microenvironment. Thus, faced with the same training, some athletes will develop iterative muscular lesions and more disabling repair deficits than others without knowing the reason of this greater susceptibility. Indeed, the links between the genotype of the skeletal muscle fiber and its response to exercise, as well as the regulation of muscle mass are poorly understood. Yet, in young adults, up to 70% of the observed variability in muscle strength and size is hereditary. This heritability of muscle size and strength seems to be lower in older people, probably related to increased comorbidity. Numerous experiments with athletes subjected to the same resistance exercise training have identified good and bad hypertrophic skeletal muscle responders. However, genetic variants that contribute to skeletal muscle strength and mass are largely understudied while a growing body of evidence indicates that epigenetic effectors, which modulate gene expression, may contribute to human muscle response heterogeneity to the same mechanical stress. Thus, to date, no analysis of the role of the interaction between genetic and epigenetic factors involved in the muscle functional response to exercise exists. The main hypothesis is that the epigenetic status of muscle stem cells (satellite cells) is an important contributor in muscle mass response to exercise by modulating chromatin architecture. Thus this study will identify the epigenetic modifications induced by training and their interaction with the genetic factors involved in the response of the biological function of the satellite cells to this training and on the other hand, to be able to link it to a blood signature.