Longitudinal Collaborative Investigation of Arm Pain in Paraplegia

Principal Investigators: Michael L. Boninger, MD; Alicia Koontz, PhD, RET;

Co-Investigators: Rory A. Cooper, PhD; Shirley Fitzgerald, PhD; Jeff Towers, MD

2003-2008

Maintaining independent living, attaining and maintaining health, and decreasing occurrence of secondary conditions in veterans with disabilities are priorities for the Department of Veterans Affairs. Due to lower limb paralysis, veterans with spinal cord injury (SCI) rely extensively on their upper limbs for mobility and activities of daily living.  Thus, any loss of upper limb function significantly affects mobility and independence. The goal of this study is to determine modifiable biomechanical factors present during wheelchair propulsion and transfers that predict the degree of pathology, clinical findings, and subjective pain in the upper limbs of individuals with paraplegia. 

This study is part of a multi-site study involving the Veterans Affairs Pittsburgh HealthCare System, Kessler Medical Rehabilitation Research and Education Corporation, and University of Washington (see also Project:  Collaboration on Upper Limb Pain in Spinal Cord Injury (CULP-SCI).  Manual wheelchair users with paraplegia undergo both biomechanics and medical diagnostic testing to assess upper limbs pathology.  For the biomechanics testing, a SmartWheel^TM, force and torque sensing pushrim originally developed at the University of Pittsburgh, is used to assess propulsion technique along with a motion capture system.  Magnetic resonance imaging is conducted on both shoulders and nerve conduction studies are used to assess median nerve health. In addition, the participants undergo physical examinations of their upper limbs and are asked questions about shoulder and wrist pain and injury.  The testing is repeated every two to three years with follow-up phone calls on changes in pain severity. 

We are currently following over 45 individuals with paraplegia some of whom we have been following for over 10+ years. In a recent cross-sectional analysis we found a relationship between shoulder joint kinetics and MRI abnormalities. More specifically, posterior directed force at the shoulder was related to coracoacromial ligament edema – a risk factor for rotator cuff injury. The same study found that internal rotation moment at the shoulder is associated with physical examination abnormalities. Two manuscripts utilizing all of the longitudinal data on wrist and shoulder pathology collected to date (Pittsburgh data only) are in preparation.  These studies focus on the relationship between subject characteristics and upper limb pathology.  We found that while nerve conduction study (NCS) findings did not change between visit 1 (baseline) and the last follow-up visit (average duration between visits of 54 ± 25 months), weight and duration of injury independent of age were strong predictors of NCS findings at the last visit. Persons with higher paraplegia had greater changes in NCS variables possibly due to supporting a greater percentage of their body weight on their wrists during transfers and weight shifts as a result of impaired trunk control.  Shoulder pathology progressed significantly between visit 1 and the last visit (average duration between visits of 48 ± 21 months).  These studies indicate that more time may be needed to detect changes in pathology and at what point symptoms begin to develop.  To continue following individuals we recently submitted a second five-year VA merit-review proposal ( Longitudinal Study of Acute and Chronic Upper Limb Pathology Following SCI) which also entails collecting ultrasound images of the upper limbs.