Inspiratory muscle training and trunk control exercises on respiratory strength and motor function in spinal muscular atrophy: randomized controlled trial.

Children with spinal muscular atrophy often have weak breathing muscles and limited trunk and motor control, so researchers wanted to know whether adding trunk exercises to a standard breathing program made a difference. In this trial, thirty-eight children were randomly assigned to either a pulmonary rehabilitation program of breathing exercises and inspiratory muscle training, or the same program plus trunk control exercises, over eight weeks. Both groups improved on their own in respiratory muscle strength and motor outcomes, with inspiratory muscle strength showing large improvements in each group. The trunk control group additionally showed gains in sitting balance, selective movement control, and upper limb function that the other group did not show.

However, when the two groups were compared directly, the differences between them were not statistically significant, even though the size of the effects suggested the combined approach might offer added benefit. This makes the trunk training component an interesting but unproven addition, based on a small sample that limits how confidently these patterns can be generalized.

If your child has spinal muscular atrophy, breathing muscle weakness and difficulty with trunk control and motor skills are common concerns. This study looked at whether adding trunk-strengthening exercises to a standard breathing training program helped children more than the breathing program alone. Thirty-eight children took part, split into two groups.

One group did breathing exercises and inspiratory muscle training, while the other group did the same plus trunk exercises. Both groups showed improvements in breathing strength and motor skills over the eight weeks.

The group that also did trunk exercises showed additional improvements in sitting balance, controlled movement, and arm and hand function that the other group did not show as clearly. When researchers compared the two groups directly, though, the differences were not statistically significant, meaning it can't be said with confidence that trunk training added extra benefit beyond chance. The study was small, so these encouraging patterns need to be confirmed in larger research before firm conclusions can be drawn about whether combining trunk training with breathing exercises truly helps more.

This is a summary of research, not medical advice. Talk to your own healthcare provider about anything affecting your care.

For clinicians weighing whether trunk control exercises add value to inspiratory muscle training programs in children with spinal muscular atrophy, this small randomized trial offers a preliminary comparison. Nineteen children received breathing exercises (diaphragmatic, pursed-lip, segmental) plus inspiratory muscle training at 30% of maximal inspiratory pressure, while another nineteen received the identical program plus trunk exercises three times weekly, over eight weeks. Both groups showed statistically significant within-group improvements in respiratory strength and motor outcomes, with maximal inspiratory pressure improving substantially in each arm (effect sizes d=1.039 and d=1.556 respectively).

The trunk control group showed additional statistically significant within-group gains in static sitting balance, selective movement control, and upper limb function (Revised Upper Limb Module) that were not reported for the pulmonary rehabilitation group alone. Critically, between-group comparisons did not reach statistical significance, so the trial does not establish that trunk training produced a superior outcome to breathing training alone, despite effect sizes described as clinically relevant. The small sample size across two arms of nineteen each limits statistical power and generalizability, and within-group improvement cannot be assumed to reflect a between-group treatment effect.

This study informs feasibility and signals a direction for further investigation rather than establishing a practice-changing addition to respiratory rehabilitation protocols.