Researchers in the department of occupational therapy at Kaohsiung Medical University, Kaohsiung City, Taiwan, have studied how the height of a wheelchair backrest can impact the way consumers propel their chairs.
The study involved 36 participants, all of whom had spinal cord injuries ranging from the T8 to the L2 level. In a university laboratory, the 26 men and 10 women in the project propelled their chairs while on a treadmill.
The treadmill was set at two measurements — level, and 3 degrees of slope — and study participants used both higher (16-inch) backrests and lower backrests that had been set at 50 percent of their trunk length.
The main outcome measures, the researchers stated, were cadence, stroke angle, peak shoulder extension angle, shoulder flexion/extension range of motion, and mechanical effective force.
In their abstract, published by the American Congress of Rehabilitation Medicine in February 2012, the researchers said, “Pushing with the low backrest height enabled greater range of shoulder motion, increased stroke angle, push time and reduced cadence regardless of whether the treadmill was level or sloped.”
Researchers added, “A lower cadence can be achieved when pushing with a lower backrest, which decreases the risk of developing upper-limb overuse-related injuries. However, postural support, comfort and other activities of daily living must also be considered when selecting a backrest height for active, long-term wheelchair users.”
To read the full abstract, go to ncbi.nlm.nih.gov/pubmed/22325682
