Acute Tendon and Nerve Responses to Exercise

Background: Manual wheelchair propulsion is a primary source of mobility for many
individuals with spinal cord injury (SCI). Propelling a manual wheelchair over an extended
period often leads to arm pain and, subsequently, to secondary disability. Over 50% of
manual wheelchair users with SCI experience arm pain that limits their activities of daily
living. The prevalence of shoulder pain and carpal tunnel syndrome among manual wheelchair
users is between 31% and 73%, and 49% and 73% respectively. A circuit training protocol has
been developed to strengthen and protect the muscles of people with SCI, and has been shown
to improve muscle strength and endurance, and reduce HDLcholesterol levels.

Purpose: The purpose of this study is to use ultrasound to analyze the effects of a bout of
circuit training on the upper extremity of persons with SCI and able-bodied controls.

Hypotheses: All subjects will show an increase in nerve cross-sectional area after
participation in the circuit training protocol. Nerves and tendons will become less
echogenic after participation in the circuit training protocol. These changes will be more
pronounced in persons with SCI.

Methods: Data collected will include history of pain, a physical exam, and ultrasound images
of the nondominant upper extremity before and after a bout of circuit training, which
includes exercises lifting weights and using an arm cycle. Before circuit training,
ultrasound images will be collected once. After the circuit training, ultrasound images will
be collected every 10 minutes over an hour. These images and will be used to measure the
health and properties (such as size) of nerves, muscles, and tendons in the arm. Changes in
these properties after a bout of circuit training will be related to history and physical
exam information.