Changes in real-time muscle performance due to stretch-shortening cycle range of motion

Details

• Personal Author:
  Baker BA ; Cutlip, Robert G. ; Geronilla KB ; Kashon M
• Description:
  PURPOSE: To investigate the effect of range of motion (ROM) on stretch-shortening (S-S) cycle-induced muscle injury in real-time using force and work parameters. METHODS: Testing was performed on dorsiflexor muscles of Sprague-Dawley rats in vivo. Animals were randomly assigned to a long ROM group (L-Inj) or short ROM group (S-Inj). The S-Inj group received 7 sets of 10 S-S cycles at 500 degrees/s between 70 degrees-120 degrees ankle angle, whereas the L-Inj group received the same protocol between 90 degrees-140. Dorsiflexor muscles were electrically stimulated for 2.8 s each set and sets were administered every minute. Force and angular position were recorded continuously for each set. The force data collected during the S-S cycles were used to calculate peak, minimum, mean, and cyclic forces for each S-S cycle. Peak force was the maximum force during S-S cycles. Minimum force was the isometric force prior to each S-S cycle. Mean force was the average eccentric force during each S-S cycle. Cyclic force was the magnitude of eccentric force enhancement. The force and angular position data were used to calculate negative, positive, and net work for each S-S cycle. Negative work was the work absorbed in the eccentric phase of each S-S cycle. Positive work was the work performed in the concentric phase of each S-S cycle. Net work is the difference between negative and positive work. RESULTS: The different ROMs led to different force profiles for the two injury groups. ROM did not significantly affect peak force and mean force from Set 1 to Set 7 of the S-S cycles (p = 0.813 and 0.265, respectively). However, ROM did affect cyclic force and min force (p <0.0001 for both parameters). Real-time changes in negative work, positive work, and net work did not differ with ROM (p = 0.878, 0.879, and 0.652 respectively) but did change significantly from Set 1 to Set 7 (p = 0.001, 0.04, and 0.001, respectively). CONCLUSIONS: Longer ROM during S-S cycles resulted in a larger deficit in real-time muscle performance measures (cyclic force and minimum force). Real-time muscle performance measures also were sensitive to S-S cycle induced muscle injury. [Description provided by NIOSH]
• Subjects:
  Animals Laboratories Musculoskeletal Diseases Musculoskeletal System Occupational Health Safety
• Keywords:
  Force Injuries Laboratory-animals Mechanical-properties Muscle-contraction Muscle-function Muscle-stress Muscle-tension Muscle-tissue Muscles Musculoskeletal-system Musculoskeletal-system-disorders Work-capability

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• ISSN:
  0195-9131
• Document Type:
  Text
• Genre:
  Abstract or Summary
• Place as Subject:
  OSHA Region 3 ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  HELD - Health Effects Laboratory Division
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  35
• Issue:
  5
• NIOSHTIC Number:
  nn:20044070
• Citation:
  Med Sci Sports Exerc 2003 May; 35(5)(Suppl 1):S387
• Federal Fiscal Year:
  2003
• Peer Reviewed:
  False
• Source Full Name:
  Medicine and Science in Sports and Exercise
• Supplement:
  1
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:82c9a87a539a433dd81fd8dbbd8e2464304e00c1daa81dee910505ba1e5e0a1e1470b88c6d122d03a11cc90db5d5af074beaea6de88498f2944c94bd9d2d57dd
• Download URL:
  https://stacks.cdc.gov/view/cdc/199920/cdc_199920_DS1.pdf
• File Type:
  [PDF - 37.39 KB ]