In Vivo Forces Generated by Finger Flexor Muscles Do Not Depend on the Rate of Fingertip Loading During an Isometric Task

Details

• Personal Author:
  Diao E ; Kursa K ; Lattanza L ; Rempel D
• Description:
  Risk factors for activity-related tendon disorders of the hand include applied force, duration, and rate of loading. Understanding the relationship between external loading conditions and internal tendon forces can elucidate their role in injury and rehabilitation. The goal of this investigation is to determine whether the rate of force applied at the fingertip affects in vivo forces in the flexor digitorum profundus (FDP) tendon and the flexor digitorum superficialis (FDS) tendon during an isometric task. Tendon forces, recorded with buckle force transducers, and fingertip forces were simultaneously measured during open carpal tunnel surgery as subjects (N=15) increased their fingertip force from 0 to 15N in 1, 3, and 10s. The rates of 1.5, 5, and 15N/s did not significantly affect FDP or FDS tendon to fingertip force ratios. For the same applied fingertip force, the FDP tendon generated more force than the FDS. The mean FDP to fingertip ratio was 2.4+/-0.7 while the FDS to tip ratio averaged 1.5+/-1.0 (p<0.01). The fine motor control needed to generate isometric force ramps at these specific loading rates probably required similar high activation levels of multiple finger muscles in order to stabilize the finger and control joint torques at the force rates studied. Therefore, for this task, no additional increase in muscle force was observed at higher rates. These findings suggest that for high precision, isometric pinch maneuvers under static finger conditions, tendon forces are independent of loading rate. [Description provided by NIOSH]
• Subjects:
  Musculoskeletal Diseases Musculoskeletal System Occupational Health Risk Assessment Risk Factors Safety
• Keywords:
  Author Keywords: Hand Carpal-tunnel-syndrome Force Hand-injuries Humans In-vivo-studies Injuries In Vivo Muscles Musculoskeletal-system Musculoskeletal-system-disorders Rate Risk-factors Tendon

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• ISSN:
  0021-9290
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  California ; OSHA Region 9
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  38
• Issue:
  11
• NIOSHTIC Number:
  nn:20028838
• Citation:
  J Biomech 2005 Nov; 38(11):2288-2293
• Contact Point Address:
  Department of Bioengineering, University of California-San Francisco, 1301 South 46th Street, Building 163, Richmond, CA 94804, USA
• Email:
  rempel@itsa.ucsf.edu
• Federal Fiscal Year:
  2006
• NORA Priority Area:
  Disease and Injury: Musculoskeletal Disorders of the Upper Extremities
• Performing Organization:
  University of California, Richmond, California
• Peer Reviewed:
  True
• Start Date:
  19980701
• Source Full Name:
  Journal of Biomechanics
• End Date:
  20030630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:50360f81d9ddc5c84922156938e9dbd389e3d7f27ccaf22b174a8c80a90ff0dddf6ccdfcee84bbed3435159b14a058c06a04d840b39f88263e7d4f73024d2b65
• Download URL:
  https://stacks.cdc.gov/view/cdc/189943/cdc_189943_DS1.pdf
• File Type:
  [PDF - 319.51 KB ]