Effect of Intensive Segmental Trunk Training on Upper Extremity Function and Seated Postural Stability in Children With Spastic Diplegic Cerebral Palsy

This single-blind randomized controlled trial investigated the efficacy of intensive segmental trunk training (ISTT) as a targeted intervention for improving seated postural control and upper limb function in children with spastic diplegic cerebral palsy (CP). Trunk control deficits are a hallmark impairment in this population, contributing to compromised upper extremity function, reduced seated stability, and limitations in activities of daily living. While conventional physical therapy often addresses trunk control indirectly, this study evaluated whether a structured, segment-specific approach yields superior outcomes.

Thirty children aged 4-12 years with spastic diplegic CP and Gross Motor Function Classification System (GMFCS) levels I-III were recruited from outpatient neurorehabilitation center. Inclusion required moderate trunk control impairment, defined as a score of ≤ 3 on the Trunk Control Test (TCT) item assessing sitting without arm support. Children with uncontrolled seizures, Botulinum toxin injections within the preceding six months, orthopedic surgery within the past year, or cognitive impairment that would preclude task comprehension were excluded.

Participants were randomly assigned to either the ISTT group (n = 15) or the control group (n = 15) using a sealed envelope method with concealed allocation. The ISTT group received specialized training targeting segmental trunk control at the thoracic, lumbar, and pelvic levels. Training sessions, conducted five times weekly for eight weeks (40 sessions total, 45 minutes each), incorporated graded exercises progressing from static to dynamic sitting balance. Key ISTT components included pelvic tilt facilitation, isolated thoracic and lumbar segmental mobilization during weight shifting, trunk rotation with reaching tasks, and perturbation-based reactive balance training using a tilt board. Exercises were progressively advanced based on individual tolerance and performance.

The control group received standard physical therapy of equal duration and frequency, emphasizing neurodevelopmental treatment (NDT) principles, passive stretching of lower extremity muscles, strengthening of the lower limbs, and gait training.

Outcome measures were assessed at baseline, immediately post-intervention (week 8), and at a four-week follow-up. The primary outcomes were seated postural stability, measured by the Segmental Assessment of Trunk Control (SATCo) and the Trunk Control Test (TCT). Secondary outcomes included upper extremity function, assessed via the Quality of Upper Extremity Skills Test (QUEST) and the Box and Block Test (BBT), and gross motor function, measured by the Gross Motor Function Measure (GMFM-88). All assessments were performed by a blinded pediatric physical therapist.

A priori sample size calculation was performed based on pilot data with an effect size of 0.6, alpha of 0.05, and power of 0.80, yielding a minimum of 13 participants per group. Between-group differences were analyzed using repeated measures ANOVA, with post-hoc Bonferroni corrections. Within-group pre-post comparisons used paired t-tests. Effect sizes were calculated using Cohen's d.

The study was approved by the institutional ethics committee. Written informed consent was obtained from parents or legal guardians.