An Evaluation of the Contact Forces on the Fingers When Squeezing a Spherical Rehabilitation Ball

Details

• Personal Author:
  Sinsel EW ; Warren CM ; Welcome DE ; Wu, John Z.
• Description:
  The rehabilitation squeeze ball is a popular device to help strengthen the hand, fingers and forearm muscles. The distributions of the contact pressure in the interface between the therapy ball and hand/fingers can affect the joint moment of each of the individual fingers, thereby affecting rehabilitation effects. In the current study, we evaluated the contact force distributions on the fingers when gripping a spherical object. Eight female adults [age 29 (9.1) years, mass 64.6 (7.1) kg, height 163.5 (1.9) cm, hand length 17.2 (0.7) cm] participated in the study. Contact force sensors were attached to the middle of the palmar surfaces of the distal, middle, and proximal phalanges of the four fingers in the longitudinal direction. In order to evaluate the effects of the ball stiffness on the contact force distributions on the fingers, subjects were requested to perform quasi-static gripping on a standard tennis ball and on a rehabilitation ball. The tennis ball is much stiffer and experiences smaller deformation under compression compared to the rehabilitation ball. We analyzed the force share among the distal, middle, and proximal finger segments, when subjects gripping balls of different stiffnesses (tennis ball vs. rehabilitation ball) and at three different grip efforts. Our results indicated that the grip force is contributed about 60% and 40% by the middle/ring fingers and by the index/little fingers, respectively. These characteristics are independent of the grip force levels and stiffness of the contact surface. [Description provided by NIOSH]
• Subjects:
  Biomechanical Phenomena Musculoskeletal Diseases Musculoskeletal System Occupational Health Safety
• Keywords:
  Author Keywords: Hand Biomechanics Fingers Force Grip Hand Injuries MSD Musculoskeletal Disorders Physical Therapy Spherical Ball
• ISSN:
  0959-2989
• Document Type:
  Text
• Genre:
  Journal Article
• 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:
  29
• Issue:
  5
• NIOSHTIC Number:
  nn:20053702
• Citation:
  Biomed Mater Eng 2018 Sep; 29(5):629-639
• Contact Point Address:
  John Z. Wu, NIOSH, 1095 Willowdale Road, Morgantown, WV 26505
• Email:
  jwu@cdc.gov
• Federal Fiscal Year:
  2018
• NORA Priority Area:
  Construction ; Manufacturing
• Peer Reviewed:
  True
• Source Full Name:
  Bio-Medical Materials and Engineering
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:1548f4e8760d8fb1d8c564698ac7fc54c3c604f30e89468c5ad8a758b7b2c317702b5eccd9bfee103543ff17156a4938584560c51b7121b8e26432460d150bc3
• Download URL:
  https://stacks.cdc.gov/view/cdc/216415/cdc_216415_DS1.pdf
• File Type:
  [PDF - 720.00 KB ]