Motor Function of Children with SMA1 and SMA2 Depends on the Neck and Trunk Muscle Strength, Deformation of the Spine, and the Range of Motion in the Limb Joints

Abstract

The purpose of this study was to investigate the functional relationships between selected ranges of motion of the neck, upper and lower limbs, the strength of the neck and trunk muscles, postural parameters, and the motor function of children with SMA1 and SMA2—27 children, aged 6 months-15 years, with genetically confirmed spinal muscular atrophy type 1 (19 children) and 2 (8 children) undergoing pharmacological treatment. All children were examined, according to the methodology, including the motor function evaluation, measurement of selected ranges of motion, assessment of postural parameters, and measurement of neck and trunk muscle strength. The functional status of 15 children was assessed with the CHOP INTEND (CHOP group) scale and of 12 children with the HFMSE (HFMSE group). The results obtained showed that, in children examined with the CHOP scale, greater limitation of flexion in the shoulder joints was observed. As the deformation of the chest increased, the functional abilities of children deteriorated. In participants examined with the CHOP group, the ranges of neck rotation decreased with the increase of the chest deformity. In the HFMSE group, the ranges of head rotation showed a strong relationship with some parameters of muscle strength and the sum of the R coefficients. Participants showed many significant relationships between the range of motion in the neck and joints of the limbs, with more significant relationships in the CHOP group. The following conclusions were made: motor skills of children with SMA depend on muscle strength, range of motion, and deformities of the spine and chest; the development of scoliosis adversely affects the motor function, ranges of motion, and muscle strength; and movement ranges are related to motor skills and strength values.

Prospective Analysis of Functional and Structural Changes in Patients with Spinal Muscular Atrophy—A Pilot Study

“…A manual containing all the procedures for applying the scales was used during the assessment. All items were tested without using a brace or orthoses [ 21 , 22 , 27 , 28 ].…”

“…The evaluated parameters included shoulder flexion (SF) and abduction (AbS), elbow flexion (EF), forearm pronation (PF) and supination (SF) in the upper limb, as well as hip flexion (HF), knee flexion (KF) and ankle dorsiflexion (AD—ankle dorsiflexion) in the lower limb. In addition, four parameters for detecting early musculoskeletal changes that predispose to scoliosis formation were examined [ 4 , 19 , 28 ]. The supine angle of trunk test (SATR), measuring the angle of upper (SATR-U) and lower (SATR-L) trunk rotation, and pelvic obliquity (PO), determining the value of pelvic tilt angle, were examined using a scoliometer.…”

“…Other parameters included cervical rotation test (CR), presenting the extent of cervical spine rotation, and hip extension (HE). Both parameters were measured using a plurimeter [ 4 , 19 , 28 ].…”

“…The current literature shows only one publication about the relationship between structural changes and motor function in children with SMA undergoing pharmacological treatment, which we believe affects physiotherapeutic assessment [ 28 ]. Moreover, previous publications presented functional improvement based only on total scale results, which is one of the limitations of the scales used in clinical practice.…”

Muscle impairment and nusinersen affect variability in patients with spinal muscular atrophy type 2 and 3: a retrospective cohort study

“…In addition, the assessment with both baseline muscle MRI score and Cobb angle correlated with the nusinersen e cacy. Technical di culty of nusinersen administration in patients with severe scoliosis have been addressed [20,21], and it has been shown that deformation of spine correlates to the motor function in patients with SMA [22]. However, there were scarce information on how the severity of scoliosis affects the effect of nusinersen.…”