Core Stability, Trunk Position Sense, Balance and Functional Mobility in Patients With Multiple Sclerosis

Balance was assessed by Biodex Biosway Portable Balance System (Biodex Medical Systems Inc., Shirley, New York). Postural Stability (PS), Limits of Stability (LOS) and Modified Sensory Organization Tests (MSOT) were evaluated with this system. PS test assesses static balance during standing up by the ability to hold the center of gravity on the support surface. The test was performed on both feet and on the left and right foot separately. LOS test assesses how much the center of gravity is displaced on the support surface without losing balance during the standing position. MSOT assesses the effects of somatosensory, visual and vestibular senses on postural control during the standing position. It evaluates the sensory component of balance in two different visual conditions and on two different support surfaces.

Timed Up and Go (TUG) tests were used to evaluate functional mobility. The TUG measures the time it takes a subject to stand up from an armchair, walk a distance of 3 m, turn, walk back to the chair and sit down. Time was recorded in seconds with a stopwatch.

Core endurance and core strength, which are two specific components of core stability, were evaluated separately. Trunk flexor, trunk extensor, right and left side bridge and prone bridge tests were applied to assess the endurance of the core muscles. Tests were terminated when the subjects said they could not continue the test or when the test position was broken. A stopwatch was used for the measurements and the results were recorded in seconds. The power of core muscles was evaluated with sit-ups and modified push-ups tests. It was recorded how many times the subject could do each test for 30 seconds. The tests were repeated twice and the best measurement score was recorded for use in the statistical analyses.

Trunk position sense was evaluated by the trunk reposition test with Dualer IQ digital inclinometer (J-TECH medical, Salt Lake City, UK, USA). Measurements were made in two levels: lumbosacral (LS) and thoracosacral (TS) regions. The testing took place while standing under three visual-surface conditions. Participants flexed the trunk approximately 30° in the sagittal plane, holding the position for a count of 3 seconds (position 1) and then participants attempted to repeat the previously attained angle. Participants indicated verbally when they felt they had reached the angle and held their position for a count of 3 seconds (position 2). The absolute difference in degrees between positions 1 and 2 was defined as the trunk reposition error (TRE) degree. Participants generated five scores for each visual-surface condition. For each condition, the highest and lowest scores were discarded and the mean of the remaining three scores represented the TRE score