Quantitative description of upper extremity function and activity of people with spinal muscular atrophy

• Published in: Journal of neuroengineering and rehabilitation Vol. 17; no. 1; p. 126
• Main Authors: Janssen, Mariska M H P, Peeters, Laura H C, de Groot, Imelda J M
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 11.09.2020; BioMed Central; BMC
• Subjects: 3D motion analysis; Adolescent; Adult; Age; Amplitudes; Analysis; Arm; Atrophy; Balances (scales); Child; Development and progression; Electromyography; Female; Forearm; Hand; Humans; Joints (anatomy); Male; Mathematical analysis; Middle Aged; Monitoring; Muscle function; Muscle strength; Muscle Strength - physiology; Muscle torque; Muscle, Skeletal - physiology; Muscular Atrophy, Spinal - physiopathology; Neuromuscular diseases; Participation; Range of motion; Range of Motion, Articular - physiology; Shoulder; Spinal muscular atrophy; Surface electromyography; Telemedicine; Torque; Upper Extremity - physiopathology; Upper limb; Wheelchairs; Wrist; Young Adult; Netherlands; Range of motion; Surface electromyography; Upper limb; 3D motion analysis; Muscle torque; Spinal muscular atrophy
• ISSN: 1743-0003; 1743-0003
• DOI: 10.1186/s12984-020-00757-4

Therapeutic management of the upper extremity (UE) function of people with spinal muscular atrophy (SMA) requires sensitive and objective assessment. Therefore, we aimed to measure physiologic UE function of SMA patients with different functional abilities and evaluate the relation between these physiologic measures and functional UE scales. 12 male and 5 female SMA patients (mean age 42 years; range 6-62 years) participated in this explorative study. Concerning the physiologic level, the maximal muscle torque, the maximal and normalized surface electromyography (sEMG) amplitudes, and the maximal passive and active joint angles were measured. Concerning the activity level, the Performance of the Upper Limb (PUL) scale was used, and hand function was examined using the Nine-Hole Peg Test and the Timed Test of In-Hand Manipulation (TIHM). Outcome measures that significantly related to the functional ability were: the PUL score (all dimensions); the finger to palm task of the Timed TIHM; biceps, triceps, and forearm extensor strength; and the active range of motion of shoulder abduction, shoulder flexion, and wrist extension. In addition, the following physiologic variables were related to the activity level (PUL score): hand function (the Nine-Hole Peg Test; R  = - 0.61), the Timed TIHM (R  = - 0.53), the maximal muscle torque (R  = 0.74), the maximal sEMG amplitude (R  = 0.79), and the maximal active joint angle (R  = 0.88). Muscle functions in SMA patients are already affected before activity limitations are noticeable. Consequently, monitoring the maximal muscle strength and the normalized muscle activity during task performance could play a role in the early detection of UE limitations. The mechanism behind the loss of arm activities due to SMA is primarily caused by decreasing muscle capacity, which influences the ability to move an arm actively. In clinical practices, these dimensions should be considered separately when monitoring disease progression in order to better evaluate the need for interventions.