Analysis of Upper Limb Sinergies in Multiple Sclerosis Subjects during Common Daily Actions
Upper limb impairments prevent to perform both simple tasks, as moving an object, and ADL (e.g. eating, dressing and grooming) in about 65% of people with MS (PwMS)1, usually characterized by compromised muscle activation patterns, reduction in muscle strength, loss of coordination, tremor and fatigue. Thus, behavioral measures could improve the understanding of MS motor control alterations facilitating the design of novel rehabilitative treatments.
Here, we proposed simple exercises to investigate and characterize upper limb motor performance and muscle activity in PwMS.
The subjects were seated in front of a table with the right hand in the right corner. At the “Go!” they had to grasp an object in front of them, bring it to their mouth, place the object in its original position and return her/his hand to the starting position. The objects were: (i) two black varnished bottles filled at different levels (287 and 785 g); (ii) a plastic glass; (iii) a spoon placed in an empty plate. Both (ii) and (iii) were empty or filled with water. The subjects had to perform the task in the most natural way possible. 10 trials for each condition were performed. We recruited at Italian Multiple Sclerosis Society (Genoa, Italy) 10 healthy subjects (HS) (age: 49±14 ys) and 10 RR PwMS (age: 50±13 ys, EDSS < 3) without relapses in the last three months and absence of neurological signs and symptoms at upper limbs. All subjects were righthanded and their movements were evaluated with kinematics (markers placed on right acromion, left acromion, C7, sternum, elbow, wrist, metacarpus) and electromyography (right triceps brachii long and lateral head, biceps brachii short and long head, brachialis, brachioradialis, infraspinatus, latissimus dorsi, upper trapezius, rhomboideus and pectoralis major, anterior, medial and posterior deltoid, extensor and flexor carpi radialis).
PwMS significantly reduced movement smoothness with respect to HS and high correlation was found with the self-reported disability degree (Abilhand). In particular and more interesting, PwMS showed abnormalities in the muscular functions during the object lifting phase, whereas the other phase of the movement did not affect.
A more extensive analysis of kinematic and electromyography should be performed and results verified on a larger population and other ADL.