What is the minimum torque required to obtain passive elbow end range of motion?

Gait Posture. 2022 Mar:93:235-239. doi: 10.1016/j.gaitpost.2022.02.010. Epub 2022 Feb 15.

Abstract

Background: Passive range of motion is a common clinical assessment. The point at which passive end range of motion is measured is typically described by the 'end-feel'of the joint.

Research question: What is the minimum amount of torque required to obtain passive elbow flexion and extension in children?

Methods: Twenty-five children (age, 7.5 ± 1.6 years-old), who had previously sustained unilateral distal humeral fractures, participated in this prospective study.Passive elbow flexion and extension was measured at least 8 weeks and up to one year out of cast. Motion capture cameras were used to track twenty-one reflective markers placed on subjects and two markers attached to the pad of a force transducer.Five trials of passive range of motion (flexion and extension) were performed on both arms. Elbow joint moments were calculated as products of the forces applied and lengths to the elbow centers. A one way ANOVA was used to determine differences in moments for flexion and extension for both involved and uninvolved limbs. Pairedsamples t-tests were used to determine differences between the involved and the uninvolved limbs for both maximum flexion and extension.

Results: There was no difference in the minimum mean joint moment (2.7 ± 1.1 Nm) at end range of motion. However, differences in passive range of motion was found between involved and uninvolved elbows (flexion p < .001; extension p = .001).

Significance: The results demonstrate therapists obtained end range of passive elbow flexion and extension applying the same amount of minimum torque. A small torque is sufficient to achieve end range of elbow motion for children. This torque can be used in guiding clinical practice for assessing passive range of elbow motion in pediatric population. Because of a paucity of data for any joint, future research developing force data for other joints should be conducted.

Keywords: Elbow; Humeral fractures; Kinematics; Kinetics; Pediatric.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Child
  • Child, Preschool
  • Elbow
  • Elbow Joint*
  • Humans
  • Prospective Studies
  • Range of Motion, Articular
  • Torque