A comparison of forefoot pressures in newly diagnosed rheumatoid arthritis patients and non-rheumatic subjects in Malta.

Abstract

Purpose of the study

The objective of this study is to assess peak plantar pressures in the forefoot region of patients with newly diagnosed Rheumatoid Arthritis (RA) as compared to Non-Rheumatoid Arthritis participants from the general population in Malta.

Research design and method

A quasi-experimental unmatched study was conducted in the Podiatry Department at Birkirkara Health Centre. Ten Rheumatoid Arthritis participants were selected from the Rheumatology Clinic at Mater Dei Hospital. The other ten participants were selected from the general population. Participants were recruited during the period commencing June 2008 and ending October 2008. Each group consisted of seven females and three males between the ages of 30 to 55 years. Every RA participant was matched for age, gender and weight to another participant from the general population. This was done to exclude any known external factors that could influence the peak plantar pressure results recorded. All participants recruited were asked to attend the Podiatry Department at Birkirkara Health Centre for pressure measurement using the HR Mat® system. Prior data collection all participants were weighed using a digital portable scale and the result was used to calibrate the pressure mat. Any hyperkeratotic lesions present were debrided so as not to increase the pressure recorded. Peak pressure data was only recorded for the participant's dominant foot using the two step protocol. A period of acclimatization was given to all participants so to adapt well to the environment prior data collection. The forefoot was divided into specific regions which were the Hallux, 1st metatarsophalangeal joint (MPJ), 2nd_4th MPJs and the fifth MPJ for peak plantar pressure measurement. From the recorded data five trials of each foot mask were selected by the researcher on basis of best practice data selection.

Results and conclusions

From the collected data it was found that there was no significant difference (p-value 0.05) in peak plantar pressure at the Hallux region between the RA and the Non-RA groups. However, there was statistical difference (p-value 0.05) in all the other regions. The RA group had higher significance pressure underneath the 1st and 2nd- 4th MP J regions whilst the Non-RA had higher peak pressures (p-value 0.05) underneath the 5th MPJ. The results showed that even at an early stage of RA, forefoot pressures are shifted towards the medial MPJs. This pressure distribution is not due to a compensatory process to pain as all participants confirmed to be pain free during the study. This implies that early podiatric management for the increased medial forefoot pressures should be considered. The need for regular foot pressure monitoring and assessment was also highlighted as these give valuable insight in disease progression. Need for further research is recommended to investigate the same patients over an adequate period to determine pressure distribution during RA progression.