Handcycling biomechanics during and after high and moderate intensity exercise

Halloran, Kellie M.

Permalink

https://hdl.handle.net/2142/127130 Copy

Description

Title

Handcycling biomechanics during and after high and moderate intensity exercise

Author(s)

Halloran, Kellie M.

Issue Date

2024-07-29

Director of Research (if dissertation) or Advisor (if thesis)

Kersh, Mariana E

Doctoral Committee Chair(s)

Kersh, Mariana E

Committee Member(s)

• Hsiao-Wecksler, Elizabeth T
• Rice, Ian
• Hernandez, Manuel

Department of Study

Mechanical Sci & Engineering

Discipline

Mechanical Engineering

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

• shoulder
• wheelchair
• biomechanics
• exercise
• spinal cord injury

Abstract

Alternative exercise modes for people with spinal cord injuries (PwSCI) are necessary to improve cardiovascular health and reduce shoulder injuries. High intensity interval training (HIIT) is a promising option due to its cardiovascular effectiveness, but the effect of HIIT on shoulder biomechanics during handcycling is still unknown. This thesis bridges a gap in our understanding of the effect of exercise intensity and rest on shoulder biomechanics (kinematics, torques, and muscle forces) during handcycling and their effect on post-exercise power. Twenty wheelchair users participated in this study. Subjects completed three exercise protocols: an incremental test to determine baseline fitness levels and peak power output (PPO), a HIIT session, and a moderate intensity continuous training (MICT) session. Motion capture, applied handle forces and torques, and electromyography were collected during exercise. In Aim 1, I used a musculoskeletal model of the shoulder to calculate shoulder joint angles and torques with inverse kinematics and inverse dynamics. While there were few kinematic differences, there were notable differences in the joint torques between the two tasks. Torques during HIIT were 35% higher compared to MICT. The change in torques during the course of exercise was activity dependent, with the plane of elevation and rotation torques increasing during MICT and the elevation torques increasing during HIIT. In Aim 2, I decomposed the shoulder joint torques into individual muscle forces. Increases in muscle forces in HIIT compared to MICT occurred primarily in the pull phase, with the subscapularis having the highest increase in maximum muscle force. The most commonly torn rotator cuff muscle forces (supraspinatus, infraspinatus, and subscapularis) were within the ultimate tendon loading force for both HIIT and MICT, with safety factors ranging from 1.9-4.0. The effect of MICT and HIIT on post-exercise activity was the focus of Aim 3. The power output, work, and applied forces were compared during 15-second sprints before and after exercise. Most subjects were potentiated or not affected following both HIIT and MICT, with an 11.2% and 8.95% increase in work following MICT and HIIT, respectively. Tangential forces were higher during the pull phase during the post-HIIT and post-MICT sprints. This research highlights the importance of the pull phase of propulsion, as the pull phase is where the muscle forces increase in HIIT compared to MICT and also where increases in applied forces occur in the post-exercise sprints compared to baseline. Training focused on strengthening the primary muscles used during the pull phase (deltoid, trapezius, supraspinatus, and infraspinatus) could better prepare the shoulder for high intensity exercise. There was low evidence of fatigue following either exercise protocol, which indicates that both protocols could be promising exercise options for PwSCI. However, a longitudinal intervention should be completed to assess the long-term impact of these exercises on shoulder health. With a more complete understanding of the effect of exercise intensity on shoulder biomechanics, we can begin to inform exercise recommendations, improve handcycling performance, and maintain shoulder safety to improve cardiovascular health and reduce shoulder injuries in PwSCI.

Graduation Semester

2024-12

Type of Resource

Thesis

Handle URL

https://hdl.handle.net/2142/127130

Copyright and License Information

Copyright 2024 Kellie M. Halloran

Owning Collections