Crutch handle design: effect on palmar loads during ambulation.

OBJECTIVE

To compare loads, load distributions, pressures, and areas of weight-bearing on the palm for forearm crutches with cylindrical and wide handles during ambulation to determine if one handle type produced greater loads on the carpal tunnel region.

DESIGN

Single-group repeated measures of normal adults; descriptive study of patients who were long-term crutch users. Data were collected from six palmar regions using an F-Scan system.

SETTING

Center for neuromuscular disorders in a hospital.

PARTICIPANTS

Thirty normal volunteers and 6 patients.

MAIN OUTCOME MEASURE

Differences in loads for the palmar regions between the two handles, particularly the carpal tunnel region.

RESULTS

For the normal adults, significantly greater loads were found in two distal regions for the cylindrical handle and in one proximal region for the wide handle. Distribution of weight-bearing loads showed a similar pattern for both handles with the palm's proximal and distal radial sides having the greatest loads and the carpal tunnel region having the third highest load. The area of weight-bearing was significantly greater for the wide handle than for the cylindrical.

CONCLUSIONS

Cylindrical and wide crutch handles have similar load distributions, making it impossible to recommend one type over the other to reduce the occurrence of carpal tunnel syndrome. The wide handle distributes the loads over a greater surface area, producing less focal pressure.