Biomechanics of Wheelchair Transfers
Condition: Spinal Cord Injury
MeSH terms: Spinal Cord Injuries
Study type: Observational

Summary: 
      This is a laboratory-based study to evaluate the risk of shoulder injury associated with
      transfers between wheelchair and vehicle in persons with spinal cord injury. Four new devices
      will be compared against an unassisted transfer.
    

Detailed description: 
      Specific Aims:

      The purpose of this 3 year laboratory-based randomized crossover study is to evaluate the
      ergonomic effectiveness of four wheelchair/vehicle transfer assistive devices, including (1)
      standard transfer board, (2) Glide n' Go, ( 3) Easy Reach Lift, and (4) Ryno Lift, and to
      compare them to an unassisted manual transfer. We have targeted persons with paraplegia
      (level of injury T2-L5) to standardize physical capabilities. Our research questions are:

        1. Evaluate the impact of vehicle/wheelchair transfers on objective measures of shoulder
           kinematics, kinetics, and muscle activity, for each of the participants.

        2. Evaluate the impact of vehicle/wheelchair transfers on subjective measures of shoulder
           pain, spasticity, perceived comfort, ease, efficiency, and safety.

        3. Examine the effects of covariates (patient characteristics, SCI characteristics and
           pain) on both objective and subjective outcome measures.

      Background:

      Upper limb pain and injury are highly prevalent in persons with a spinal cord injury (SCI)
      who use a manual wheelchair for mobility. Historically, persons with paraplegia did not long
      survive the trauma of their injury, but with advances in medicine and emergency services,
      persons with SCI now have a life expectancy approaching that of the general population. For
      persons with paraplegia, paralysis of the lower limbs necessitates an over reliance on the
      upper limbs for performing wheelchair propulsion, transfers in/out of the wheelchair, and
      other mobility-related tasks. Many years of overuse of the upper extremities leads to an
      increased incidence of pain and cumulative trauma to the shoulders, elbows and wrists. Over
      50% of persons with SCI have upper extremity pain; rotator cuff tears have been reported in
      59-73%; and 40% have clinical evidence of carpal tunnel syndrome. Upper extremity
      deterioration following years of compensating for the lack of functional lower limbs in
      addition to their usual loading reduces quality of life, function, independence, and even
      life expectancy following SCI. The two most stressful mobility tasks performed by persons
      with paraplegia are wheelchair propulsion and wheelchair transfers. Several investigators
      have examined upper extremity kinematics (joint motions) kinetics (joint forces and torques),
      and muscle activity as determined by electromyography (EMG) among individuals with SCI during
      wheelchair propulsion. Comparatively few studies have addressed wheelchair transfers none of
      which offer an integrated kinematic, kinetic and EMG approach to simultaneously examine joint
      angles, moments and muscle activity.

      Methods:

      Using Vicon motion analysis technology, we propose a laboratory-based randomized evaluation
      of five vehicle transfer approaches: unassisted manual transfer, standard transfer board,
      Glide n'Go, Easy Reach lift, and Ryno lift. The selected commercially-available products
      represent the range of assistive technologies presently available for this task.

      A sample of 58 veterans with paraplegia, who use a manual wheelchair for mobility, will be
      recruited to participate in this study. Subjects will be recruited from the Tampa VA Hospital
      by means of poster advertisement. Participants will complete data collection activities
      during one four-hour session, for which they will be compensated. Subjects will be asked to
      perform a series of five randomized wheelchair-to-vehicle transfer tasks. Vicon markers
      placed on the participant's body will capture positional data. Dynamic external loads exerted
      during the transfer tasks will be measured using AMTI MC3A tri-axial load cells strategically
      mounted in a vehicle mock-up. EMG will be recorded bilaterally for major muscle groups.
      Participants will complete subjective rating scales upon completion of each of the transfers.

      The results of this study will be used to develop a clinical algorithm to assist clinicians
      with the selection of the most appropriate assistive technology for persons with disabilities
      who use a manual wheelchair for mobility. This algorithm will facilitate the individualized
      selection of assistive technologies that minimize risk for injury and maximize patient
      compliance, comfort, and satisfaction. The ultimate goal of this program of research is to
      (1) promote successful adaptation to aging with a disability, (2) reduce morbidity and
      mortality associated with wheelchair use, (3) enhance health-related quality of life, patient
      freedom, function, independence, and confidence, and (4) reduce healthcare utilization and
      associated costs.
    

Intervention name(s): Unassisted Manual Transfer; Standard Transfer Board; Glide n' Go; Easy Reach lift; Ryno lift
Intervention type(s): Device; Device; Device; Device; Device
Intervention description(s): No device assistance; Flat surface board; Flip down power lift chair; Original chair is converted to a chair that swivels out of the vehicle and lowers to wheelchair height; Lift for the wheelchair
Observational model: Case-Crossover
Time perspective: Cross-Sectional
Sampling method: Probability Sample
Study population: 
        A sample of 58 veterans with paraplegia who use a rigid manual wheelchair will be recruited
        to participate in this study.
      
Keywords: Biomechanics; Ergonomics; Spinal Cord Injury; Pain; Shoulder