1. automotive and vehicles
2. minivan

Does a lever-activated manual wheelchair decrease incidence of shoulder pathology greater than a manual handrim wheel chair in mid thoracic and above
level spinal cord injured patients?
Bryan Johnston
Physical Therapy Program Department of Orthopaedics & Rehabilitation
University of New Mexico, Albuquerque, NM
Advisor: Kathy Dieruf P.T. Ph.D N.C.S.
Abstract
Case Description
Conclusion
Spinal cord injured (SCI) patients who are full time manual wheelchair users often suffer
from shoulder pain. Research suggests that the etiology of this pain can be from wheelchair
propulsion when using a standard handrim wheelchair. The purpose of this capstone project
is to review the literature on alternative wheelchair propulsion methods, specifically a leveractivated wheelchair, and its ability to prevent shoulder pathology compared to a standard
handrim wheelchair.
Research specifically relating to the lever-activated wheelchair is scarce. One study was
found that directly related. Requejo et. al found that the lever activated wheelchair
decreased muscle activity in supraspinatus by a peak of 50% and increased distance per
stroke from .84m to 1.01m . Several other studies found that mechanical advantage and
increasing efficiency during wheelchair propulsion decreased pain in the shoulder and
increased social participation and quality of life. A lever-activated wheelchair can prevent
shoulder pathology better than a standard handrim wheelchair. By decreasing
supraspinatus activity, increasing mechanical advantage, increasing muscular efficiency,
and decreasing strokes per day, a patient with an SCI can expect to prevent shoulder
pathology or decrease current pain. By decreasing pain, these patients can increase quality
of life and maintain or regain their independence.
Mr. R. is a 46 year old white male with a complete spinal cord injury (SCI) at the level of T6. Mr. R
is considered an ASIA A (complete loss of sensory and motor function below the level of injury),
after he traumatically injured his spinal cord at T6 during a snowmobile accident in Syracuse, NY.
He has a medical diagnosis of medial subluxation and tendonopathy of the intra-articular long
head of the biceps, subscapularis tear, and supraspinatus tear. The physical therapy practice
pattern according to the Guide to Physical Therapy Practice is 4D and 4E, rotator cuff syndrome
of shoulder and allied syndromes, and disorders of bursae and tendons in the shoulder
respectively. He has received several medical interventions including corticosteroid injections to
decrease inflammation, surgery to repair torn rotator cuff muscles and tendons as well as labrum
repair, and bursectomies to remove permanently damaged and inflamed bursa. Medical
interventions were performed on his right shoulder in the following order; 2004: Surgery to R
shoulder for rotator cuff and labral tear repair, 2005-2012: Multiple corticosteroid injections 2013:
Rotator cuff repair and subacromial bursectomy, late 2013: Corticosteroid injection x2.
A lever-activated manual wheelchair will decrease incidence of shoulder pathology in
mid thoracic spinal cord patients who are full time manual wheelchair users greater
than a standard manual wheel chair. The lever-activated wheelchair has been found
to decrease muscular demand in the vulnerable rotator cuff muscles which can help
decrease the incidence of muscular tears secondary to high load and overuse. The
lever-activated wheelchair will also increase distance per stroke and decrease total
strokes per day which will allow a more sufficient amount of time for the muscles to
recover to a proper resting length before contracting again. This phenomenon will
also decrease the incidence of repetitive strain overuse injuries in this population (1).
By decreasing shoulder pathology in this population through use of the leveractivated wheelchair, research shows that social interaction will increase, as well as
overall quality of life (2).
The lever-activated wheelchair also positions the upper extremity in a different
position than a standard manual wheel chair. Instead of positioning the upper
.
extremity in an extended position to initiate the stroke, the lever-activated chair
requires a neutral glenohumeral position (1). This can be beneficial in patients who
may be suffering from impingement syndrome. Also, the lever activated chair does
not require wrist flexion or finger flexion like a standard wheelchair does. This can be
beneficial for patients with higher lesions (i.e. C5 or C6) who can recruit deltoids,
pectorals, and wrist extensors. The joint positioning of the chair allows a population
who may not have been able to use a manual chair due to lesion level or
impingement pain to reap the functional benefits of propelling a manual chair. The
lever-activated wheelchair can be a significant factor in a person with a spinal cord
injury who is trying to live a more enjoyable, pain free life.
Background
• In the United States of America, 70% of those who suffer traumatic spinal cord injuries
develop shoulder pain that is often chronic in nature. Their adaptations in using the upper
extremities to perform weight bearing, mobility, and transfer activities is a key component
to why they develop shoulder pain (1). The anatomy and joint kinematics of the shoulder
are key components to why pain arises during these high demand activities. The
structure of the human shoulder joint is not optimal for locomotion or weight bearing. Its
primary purpose is to position the hand in a precise manner, to be able to lift weights, and
to counterbalance the body during walking (2). In the population with a SCI, the shoulder
is used for activities it was not built to do, resulting in several potential pathological
conditions.
• There are few preventive strategies in place to decrease the incidence of shoulder injury
in this population who rely so heavily on use of their upper extremity for daily activities.
• This capstone project describes the prevalence of shoulder injuries in the population with
a SCI, affects of pain on daily life, and possible interventions to improve the lives of these
patients.
Introduction
The development of shoulder pain in the population with a SCI has been recognized by the
entire medical team. Some of the available, common treatments or preventive strategies are
exercise to strengthen shoulder stabilizers and increase endurance, wheelchair positioning
to allow better joint mechanics of the shoulder complex during propulsion, corticosteroid
injections to decrease inflammation and allow more space for subacromial tissues to pass,
and surgery to remove or repair permanently damaged or inflamed bursa, repair
musculotendinous structures, or shave bone to create more space. Of the several
interventions mentioned, only two are preventive measures for decreasing shoulder
pathology. Due to the high prevalence of shoulder pain in the population with a SCI , more
preventive measures need to be taken to decrease incidence of shoulder pain and maintain
high quality of life levels. One potential way of preventing shoulder pathology is by
increasing mechanical advantage, improving position of the UE, decreasing stroke number,
decreasing muscular work in the rotator cuff muscles, and increasing work at larger muscle
groups, all during wheelchair propulsion. By accomplishing all of these components there is
a potential to decrease inflammatory processes in the subacromial space due to proper joint
alignment and mechanics, decrease overuse injuries by decreasing repetition of strokes per
day, and decreasing rotator cuff injuries by shifting muscular load to larger muscle groups.
Alternate forms of wheelchair propulsion to address these issues have emerged. A leveractivated wheelchair system that allows its users to propel the wheelchair forward or
backwards by pushing or pulling long levers connected to the wheelchair axle designed to
increase mechanical efficiency, decrease stroke repetition, decrease total muscular work and
effort, and more properly align the shoulder complex has been developed.
.
.
Literature Review Key Findings
• 70% of all traumatically spinal cord injured patients surveyed had develop shoulder pain, 80%
of these individuals had diagnosed rotator cuff tears
• As age increases, odds of experiencing shoulder pain increases, OR=1.05. Highest median
intensity of pain was experienced during ramp propulsion, followed by loading chair in car, and
transferring into a car
• As pain decreased in exercise group, social interaction
improved, QOL improved, and use of
.
wheel chair was less painful.
• Implementation of Paralyzed Veterans of America’s Clinical Practice Guidelines did not
prevent pain from occurring in the shoulder of full time SCI wheelchair users.
• More than half of the force used to propel a standard wheelchair is downward to keep hand on
the rim. Full tangential force is most effective for propulsion but increases muscle work of
suprapinatus and infraspinatus which could lead to repetitive injuries.
• When a 2-speed geared manual wheelchair was used for 20 weeks, pain was reduced by
54.3% in fulltime wheelchair users with a SCI.4
• When using a lever driven wheelchair, distance increased from .84m to 1.01m , supraspinatus
activity decreased by 50% over even and graded surfaces.
References
1. McCasland, Leslie D., Elly Budiman-Mak, Frances M. Weaver, Elaine Adams, and Scott Miskevics. "Shoulder pain in the traumatically injured spinal cord patient: Evaluation of risk factors and function." Journal of Clinical Rheumatology 12.4
(2006): 179-86. Cinahl . Web. 25 Jan. 2014.
2. Kemp, B. J., Bateman, A. L., Mulroy, S. J., Thompson, L., Adkins, R. H., & Kahan, J. S. (2011). Effects of reduction in shoulder pain on quality of life and community activities among people living long-term with SCI paraplegia: a randomized
control trial [Electronic version]. The Journal of Spinal Cord Medicine, 34(3), 278-284. doi:10.1179/107902611X12972448729486
3. Requejo, Phillip, Sharon Lee, and Sara Mulroy. "Shoulder Muscular Demand During Lever-Activated vs. Pushrim Wheelchair Propulsion in Persons with Spinal Cord Injury." Journal of Spinal Cord Medicine 31.5 (2008): 568-77. Web. 9 Dec.
2013.
4. Rankin, J. W., Kwarciak, A. M., Richter, M. W., & Neptune, R. R. (2010, October 19). The influence of Altering Push Force Effectiveness on Upper Extremity Demand During Wheelchair Propulsion. Journal of Biomechanics, 43(14), 2771-2779.
doi:10.1016/j.jbiomech.2010.06.020
5. Rice, L. A., Smith, I., Kelleher, A., Greenwald, K., & Boninger, M. L. (2014, January). Impact of a Wheelchair Education Protocol Based on Practice Guidelines for Preservation of Upper-Limb Function: A Randomized Trial. Archives of Physical
Medicine and Rehabilitation, 95, 10-19. Retrieved January 5, 2014, from PubMed.
6. Alm, M., Saraste, H., & Norrbrink, C. (2008). Shoulder pain in persons with thoracic spinal cord injury: prevelence and characteristics. Journal of Rehabilitation Medicine, 40, 277-283. doi:10.2340/16501977-0173
7. Samuelsson K, Tropp H, Gerdle B. Shoulder pain and its consequences in paraplegic spinal cord-injured, wheelchair users. Spinal Cord [serial online]. January 2004;42(1): 41-46. Available from: SPORTDiscus with full text, Ipswich, MA.
Accessed January 11, 2014.
8. Finley, M. A., & Rodgers, M. M. (2007, December). Effect of 2-speed geared manual wheelchair propulsion on shoulder pain and function. Archives of Physical Medicine and Rehabilitation, 88, 1622-1627. doi:10.1016/j.apmr.2007.07.045