Investigating Fatigue, Balance, Falls and Mobility in people with Multiple Sclerosis

All subjects will be trialled in the following conditions in: - Condition A - Rest - Condition B - Walking without DorsiFlexion Assist - Condition C - Walking with DorsiFlexion Assist All subjects will be tested under each condition. The order of the conditions will be randomised. All assessments will be completed within 3 weeks, with at least 2 days between each assessment. This will ensure that results are not affected by disease progression why allowing some time to recover between assessments. Conditions Condition A: No Fatigue In Condition A, the participant will sit and rest for 6 minutes. Condition B: Fatigue-The 6 Minute Walk Test (6MWT) The participant will undertake a modified six-minute walk test (6MWT). This is a variation of the original American Thoracic Society Script.("ATS statement: guidelines for the six-minute walk test," 2002). This involves the participant walking unaided up and down a 10m straight walkway for six minutes with the use of a modified script that aims to maximise effort and test endurance.(Goldman et al., 2007) Distance will be measured every minute, as well as participants rating of perceived exertion (RPE) using the modified Borg scale.(Borg, 1982) While encouraged to continue walking throughout the test, participants are permitted to slow down, stop and rest as necessary. Heart Rate will be continually monitored throughout the 6MWT. Condition C: Fatigue + Dynamic DorsiFlexion Ankle Orthosis (DDAO) The participant will wear the same shoes as in Conditions A & B. The Dorsiflexion Assist Orthosis (DOA) (Foot-Up, Ossur) will be fitted around the ankle and underneath the laces of the shoe. This device assists ankle dorsiflexion with a dynamic elastic support attached to the shoe and no direct contact with the foot. The device therefore does not alter the participant’s existing abilities to detect pressure sensations in the sole of the foot used to assist balance control. The experiment is completed in exactly the same way as described for Condition B.