Muscle Damage and Disuse Atrophy
Muscle Disuse AtrophyLimb injury generally requires a period of recovery during which time the limb is often immobilised (e.g. with a cast or brace) resulting in a rapid loss of skeletal muscle. Despite the importance of muscle loss during injury, our understanding of how it occurs is incomplete. Several factors are likely to contribute, including a lack of muscle contraction and injury induced inflammation. In this study, the investigators will recruit healthy volunteers who will spend 7 days in a knee brace to replicate leg immobilisation. Prior to immobilisation, half of the participants will perform a single session of strenuous resistance exercise which is known to cause muscle damage and initiate an inflammatory response. This is designed to replicate the muscle damage and inflammation that occurs with injury. The remaining half of participants will not perform this exercise, allowing us to look at the additive effect of muscle damage and inflammation on muscle loss with immobilisation.
Effect of a Natural Source Supplementation on Muscle Mass
Muscle Disuse AtrophyNutrition1 morePeriods of muscle disuse are commonly experienced in young and elderly individuals as a result of short-term hospitalization or leg casting after injury. Periods of immobilization result in a profound loss of muscle mass and strength. This loss of muscle mass can have negative effects on health and the ability to carry out activities of daily living. Thus, it is very important to try to maintain muscle mass during muscle disuse. Recent research suggests that Fortetropin, which is an all-natural protein-fat complex made from fertilized hen egg yolks, can enhance muscle mass and strength with weightlifting in young men. In this study, we aim to investigate the safety and tolerability of Fortetropin and whether Fortetropin supplementation can reduce or prevent the loss of muscle mass during single-leg immobilization while you are wearing a knee brace. To make this decision, we require a study to compare Fortetropin to a placebo (something that contains the same amount of protein and energy as Fortetropin). The findings from this study will help us understand if Fortetropin supplementation is safe, tolerable, and can be used to slow muscle loss in people who undergo periods of muscle disuse (i.e. surgery, sickness).
Bed-rest, Muscle Mass and Insulin Sensitivity
Disuse AtrophyIn the present study, the effects of 7 days of bed rest on muscle mass, muscle fiber characteristics and insulin sensitivity will be determined.
Short Arc Multifidus Study
Multifidus Disuse AtrophyPatients will be performing Logan short arc banding protocols to see the effect on multifidus size
Activity Dependent Rehabilitation Model to Improve Bone and Muscle Outcomes
Disuse OsteoporosisAtrophy4 moreFor many after spinal cord injury (SCI) there is immobilization, muscle atrophy, bone loss, fracture risk during transferring (or falls), and the risk of secondary complications, and increase in attendance care and cost. It is important to develop multi dimensional rehabilitation strategies for people after SCI to enhance functional recovery towards walking, and enhance an increase in muscle and bone to potentially prepare the injured nervous system in the event of a cure. Locomotor training (Stand retraining and step re training) an activity-based rehabilitative approach generates muscle activity and provides weight bearing and joint contact kinetics, even in individuals who are unable to stand or step independently. Cross-sectional animal and human SCI studies have demonstrated that locomotor training (LT) (stand retraining and step retraining using body weight support treadmill training) has improved the capacity to stand independently and walk at faster speeds. Neuromuscular stimulation (NMS) or electrical stimulation (ES) training is a rehabilitative approach that generates muscle activity, alternating leg extension and flexion even in individuals who are unable to stand or step independently. NMS studies for individuals after SCI have shown improvements in bone density and muscle strength after cycling and resistance training. The main purpose of this study is to address whether stand retraining and NMS compared to stand retraining alone or NMS alone will increase neural and musculoskeletal gains and provide a greater functional recovery towards independent standing. This project will be completed at two sites: Kessler Foundation Research Center (the grant PI site) and Frazier Rehabilitation Institute, University of Louisville, Kentucky.
Neuromuscular Electrical Stimulation During Immobilization Due to Ankle Fractures
ImmobilizationMuscle Disuse AtrophyRationale: Situations such as fractures of the lower extremity can necessitate a prolonged period of immobilization in otherwise healthy individuals. Long-term immobilization of the lower extremity has shown to cause significant reductions in skeletal muscle mass, already occurring during the early stages of disuse. Accordingly, feasible strategies for attenuating this loss of muscle during disuse need to be pursued. Local neuromuscular electrical stimulation (NMES) offers such a potential strategy but, as yet, remains untested during prolonged muscle disuse in a clinical setting. Objective: To investigate whether twice daily local (gastrocnemius/soleus) NMES attenuates muscle loss during 2 weeks of unilateral ankle immobilization. Study design: Randomized, parallel (two groups) study design. Study population: 30 adults (18-65 y) with any form of closed ankle fractures needing surgical treatment. Intervention: Twice daily neuromuscular electrical stimulation (NMES) or no intervention. Main study parameters/endpoints: Primary: Calf muscle (gastrocnemius) cross sectional area (CSA) as determined by CT scan. Secondary: type I and II muscle fiber CSA and SC content, intramuscular triglyceride content and mRNA and protein expression of anabolic signaling proteins.
Bedrest, Feeding Pattern, and Insulin Sensitivity
AtrophyDisuse1 moreIn the present study, the investigators will assess the impact of two different feeding patterns (continuous vs intermittent) on insulin sensitivity and muscle mass following bedrest.
Strength Training Augmenting Rehabilitation
Muscle Disuse AtrophyThis project aims to determine whether a novel strength training rehabilitation protocol can diminish the negative consequences of limb immobilization and expedite the restoration of muscle function during retraining in healthy individuals.
n3 PUFA and Muscle-disuse Atrophy in Young Women
Muscle AtrophyThis study will examine the influence of n3 PUFA supplementation on the rate of muscle atrophy in women undergoing 2 weeks of unilateral limb immobilization. Assessments in skeletal muscle strength and skeletal muscle volume will also me made before, after and in recovery from immobilization.
Blood Flow Restricted Electrical Stimulation During Immobilisation
AtrophyMuscular2 moreFollowing injury or surgery to a limb, it is often immobilised to allow tissue healing. Short periods of disuse cause loss of muscle size and strength and impaired mechanical properties of tendons, which leads to reduced function. Strategies to combat these deconditioning adaptations include neuromuscular electrical stimulation (NMES), however at present its effectiveness is limited. Recent research suggests that the effects of NMES can be augmented with blood flow restriction (BFR). At present, the effect of combining these two techniques on muscle function during limb immobilisation is unknown. Furthermore, the impact of BFR training during retraining following immobilisation is unknown.