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395 Mechanomyography: ILasers for non-invasive quantification of muscle recovery from exercise induced fatigue
Mechanomyography: ILasers for non-invasive quantification of muscle recovery from exercise induced fatigue N. Rosser*, D. McAndrew & D. Iverson University Of Wollongong
Introduction: Muscle fatigue is a common clinical sign and possible precursor to musculoskeletal injury. Existing methods of detecting muscle fatigue qualify changes within muscle or across joints, but are expensive, invasive or difficult to use. A technique of mechanomyography utilising maximal percutaneous stimulation (known as the Muscle Displacement Laser {MOL}) is an easy non-invasive assessment tool, which may have considerable application in measuring muscle fatigue and determining recovery. Specifically, this study attempted to validate the MOL as a tool to measure muscle fatigue and determine the time-course of recovery from Delayed Onset of Muscle Soreness in human biceps brachii muscle. Methods: The protocol utilised concentric/assisted contractions performed in sets of 10 repetitions at 800/0 of subject's 1RM. Volitional exhaustion during concentric contractions will occur, followed by 5 assisted repetitions till absolute fatigue occurs. RPE and MOL were assessed on consecutive days till recovery was achieved. Results: Preliminary evidence suggests that the muscle was fatigued following the protocol. Differences in MOL patterns were found between pre and post fatigue trials. Maximum displacement (Dmax) and contraction time (tc) decreased while relaxation time (tr) increased. Further results are pending analysis. Discussion: The MOL was found to be a valid means of detecting muscle fatigue and recovery from fatiguing exercise. Initial results indicate the muscle does not recover until the fifth day following the stimulus. This indicates that fatigued muscles are at an increased risk of injury during this period, which has implications for modifying training and recovery for people/athletes to reduce the deleterious risk of musculoskeletal injuries.
III '.
Effect of post-exercise recovery procedures on 72hr recovery following strenuous stairclimb running
B. Dawson &E. Robey* University Of Western Australia
The purpose of this study was to compare the efficacy of common post-exercise recovery procedures, namely hot/cold water immersion, stretching, and no recovery (control) on quadriceps strength and indicators of muscle soreness/damage across 72 hours following demanding running training. After baseline measurements, Club (n=14) and Sports Institute (n=6) rowers performed the training run (~ 6km), which included between 3 to 9 multiple stair climbs of 242 steps, (up and down) completed as fast as possible on three separate occasions. After each run, participants completed a randomly assigned 15 minute set recovery; either hot/cold, stretching or control, which were repeated at 24 and 48 hours post-run. Creatine kinase, muscle soreness and quadriceps peak torque measures were taken pre and post-run, then 24, 48 and 72 hours post-run. No significant differences existed between the three post-exercise recovery treatments on any of the measured variables. Main effects for time were seen for both muscle soreness and creatine kinase. Muscle soreness for both subject groups remained significantly elevated above baseline at 72 hours post-exercise. Creatine kinase levels increased significantly post-run in both groups, but only the Club group increased further at 24 hours post-run. At 48 hours post-run these levels had returned to baseline. At 72 hours post-run values were below baseline in both groups. Quadriceps torque showed no significant differences for recovery treatment or time over the 72 hours post-exercise. Neither procedure accelerated the recovery of the measured variables at 72 hours beyond that achieved by the control condition.
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Introduction: Muscle fatigue is a common clinical sign and possible precursor to musculoskeletal injury. Existing methods of detecting muscle fatigue qualify changes within muscle or across joints, but are expensive, invasive or difficult to use. A technique of mechanomyography utilising maximal percutaneous stimulation (known as the Muscle Displacement Laser {MOL}) is an easy non-invasive assessment tool, which may have considerable application in measuring muscle fatigue and determining recovery. Specifically, this study attempted to validate the MOL as a tool to measure muscle fatigue and determine the time-course of recovery from Delayed Onset of Muscle Soreness in human biceps brachii muscle. Methods: The protocol utilised concentric/assisted contractions performed in sets of 10 repetitions at 800/0 of subject's 1RM. Volitional exhaustion during concentric contractions will occur, followed by 5 assisted repetitions till absolute fatigue occurs. RPE and MOL were assessed on consecutive days till recovery was achieved. Results: Preliminary evidence suggests that the muscle was fatigued following the protocol. Differences in MOL patterns were found between pre and post fatigue trials. Maximum displacement (Dmax) and contraction time (tc) decreased while relaxation time (tr) increased. Further results are pending analysis. Discussion: The MOL was found to be a valid means of detecting muscle fatigue and recovery from fatiguing exercise. Initial results indicate the muscle does not recover until the fifth day following the stimulus. This indicates that fatigued muscles are at an increased risk of injury during this period, which has implications for modifying training and recovery for people/athletes to reduce the deleterious risk of musculoskeletal injuries.
III '.
Effect of post-exercise recovery procedures on 72hr recovery following strenuous stairclimb running
B. Dawson &E. Robey* University Of Western Australia
The purpose of this study was to compare the efficacy of common post-exercise recovery procedures, namely hot/cold water immersion, stretching, and no recovery (control) on quadriceps strength and indicators of muscle soreness/damage across 72 hours following demanding running training. After baseline measurements, Club (n=14) and Sports Institute (n=6) rowers performed the training run (~ 6km), which included between 3 to 9 multiple stair climbs of 242 steps, (up and down) completed as fast as possible on three separate occasions. After each run, participants completed a randomly assigned 15 minute set recovery; either hot/cold, stretching or control, which were repeated at 24 and 48 hours post-run. Creatine kinase, muscle soreness and quadriceps peak torque measures were taken pre and post-run, then 24, 48 and 72 hours post-run. No significant differences existed between the three post-exercise recovery treatments on any of the measured variables. Main effects for time were seen for both muscle soreness and creatine kinase. Muscle soreness for both subject groups remained significantly elevated above baseline at 72 hours post-exercise. Creatine kinase levels increased significantly post-run in both groups, but only the Club group increased further at 24 hours post-run. At 48 hours post-run these levels had returned to baseline. At 72 hours post-run values were below baseline in both groups. Quadriceps torque showed no significant differences for recovery treatment or time over the 72 hours post-exercise. Neither procedure accelerated the recovery of the measured variables at 72 hours beyond that achieved by the control condition.
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