THE DIFFERENCE BETWEEN THE FUNCTIONAL AND MAXIMUM MOVEMENT OF THE FIRST METATARSOPHALANGEAL JOINT

Abstract

Aim: One of the issues of metatarsophalangeal joint (MTPJ) replacements is that they do not restore full range of movement (RO M). However, full RO M is not needed for functional walking. The aim of this study was to measure the difference between the functional and maximum ROM of the first metatarsophalangeal joint.

Materials & Method: The functional and maximum ROM of 32 MTPJs in 16 normal adults were measured with a video imaging system. The system first measured the ROM as the subject walked past the camera. It then measured the ROM as standing maximum extension tests were performed.

Results: During functional walking tests the mean ROM was 37.9 degrees (SD 12.2). During maximum standing extension tests the mean ROM was 64.9 degrees (SD 11.3). Therefore the functional walking ROM was only 58% of the maximum standing extension ROM, with a mean difference of 27 degrees. A paired t-test comparison showed P< 0.0001.

Discussion: MTPJ arthroplasty has previously been criticised because it does not restore full RO M. However, the results of this study suggest that the functional movements required in normal gait are significantly less than what can be maximally achieved in clinical standing extension tests. Therefore arthroplasty can be a suitable treatment if it can provide an adequate functional RO M.

Conclusion: The results of this study show that the functional range of movement required for walking is only 58% of the maximum extension ROM of the first MTP joint. Therefore, MTP joint replacements do not need to restore maximum extension, as normal gait can be achieved without this.