Biomechanical Evaluation of Independent Transfers
Principal Investigator: Alicia Koontz PhD
Co-Investigator(s): Michael L. Boninger, MD; Annmarie Kelleher, OTR/L; Megan Yarnall, BS; Emily Teodorski, BS
Funding Source: VA RR&D
Objectives
It is well established that individuals with spinal cord injury (SCI) have a high prevalence of repetitive strain injuries of the shoulder and wrist, believed to be caused by overuse of the upper extremities. Mobility, transfers and pressure relief manuveurs are a large part of the daily life of individuals with SCI. Transfers are indicated as a primary reason for the pain, however, there is a lack of research that identifies the most effective and safest way to perform a transfer activity.
The specific aims of this study are to:
1) Determine the reliability and stability of the measured kinetic and kinematic transfer variables.
2) Conduct a sensitivity analysis to assess the ability to detect changes in transfer variables.
3) Conduct a biomechanical analysis of transfers with a large group of individuals with spinal cord injury and evaluate the associations between transfer techniques used and user characteristics (e.g., such as level of injury, body weight, gender etc.) and upper limb pain and injury.
Research Design
This is a descriptive pilot study that will evaluate transfer biomechanics. Twenty-five able-bodied subjects and sixty-five subjects with spinal cord injury may be asked to perform up to 10 different transfers and each transfer type may be performed ten times and in both directions
Methodology
Demographic information, general information about transfer activities, and anthropometrics measurements of the subjects’ arms and hands will be recorded. Electromagnetic sensors, reflective markers and surface-mounted electromyographic (EMG) electrodes may be placed on the upper body to record muscle activity during the transfers.
Participants will start out seated in a wheelchair and will perform transfers to another surface such as toilet seat or tub bench. Both the wheelchair and transfer surface are securely mounted to two force and torque sensing plates. An instrumented armrest and/or grab bar capable of measuring applied forces and torques will be positioned near the participant to use when performing the transfers.
Clinical Significance
Repetitive strain injuries are very common in individuals with SCI affecting their ability to maintain an independent and healthy lifestyle. Independent living implies not only maximizing community integration, but also minimizing lost productivity and health and support care costs to society. Most individuals with SCI who lead independent lives must be able to transfer themselves in and out of a wheelchair to a variety of surfaces, such as a bed, automobile, or toilet using only the upper extremities. Knowing and practicing the most effective and safe way to transfer could improve a veteran’s functional independence and overall quality of life.