Unlocking Strength: A Practical Guide to Progressive Resistance Training for Ambulatory Children with Cerebral Palsy

For years, the role of strength training in pediatric neuro-rehabilitation, particularly for children with cerebral palsy (CP), has been a topic of debate. The fear that resistance training could exacerbate spasticity often led to a more conservative, hands-off approach. However, a growing body of evidence is not just challenging but shattering this outdated notion. A recent high-quality randomized controlled trial by Hanssen and colleagues (2022) provides compelling evidence that progressive resistance training (PRT) is not only safe but also highly effective for improving muscle strength and function in ambulatory children with spastic CP. This landmark study, published in *Frontiers in Physiology*, investigated the effects of a 12-week PRT program on lower limb muscle strength, morphology, and gross motor function. The researchers recruited 49 children with spastic CP, aged 5-11 years, classified at GMFCS levels I, II, and III. The participants were randomized into two groups: an intervention group that received the PRT program and a control group that continued with their usual care. The intervention group (n=26) engaged in a 12-week PRT program with 3-4 sessions per week. The exercises were performed in 3 sets of 10 repetitions, with the intensity aiming for 60-80% of the child's 1-repetition maximum (1RM). This intensity is crucial, as it aligns with the principles of strength training for the general population, emphasizing that a sufficient stimulus is required to elicit adaptation. The training sessions were a mix of supervised sessions with a physiotherapist and home-based sessions, a practical approach that enhances feasibility and adherence. The results of the study were impressive. The intervention group demonstrated significant improvements in knee flexion strength and functional strength, as measured by unilateral heel raises. Furthermore, significant time-effects were observed for knee extension and plantar flexion isometric strength, as well as for functional tasks like sit-to-stand and lateral step-ups. This indicates that the PRT program led to broad improvements in lower limb strength. Perhaps one of the most exciting findings was the effect on muscle morphology. While the improvements in muscle volume were not as pronounced as the strength gains, the study found that PRT helped maintain muscle size relative to skeletal growth. This is a critical finding, as it suggests that PRT can help counteract the muscle atrophy and relative weakness that often accompany growth in children with CP. Importantly, the study reported no serious adverse events, reinforcing the safety of a well-designed PRT program for this population. So, what does this mean for our clinical practice? It means we have strong evidence to support the use of PRT as a core component of our treatment plans for ambulatory children with spastic CP. We can confidently prescribe exercises like squats, lunges, step-ups, and heel raises, knowing that they can lead to meaningful improvements in strength and function. The study's protocol of 3-4 sessions per week, with 3 sets of 10 repetitions at 60-80% of 1RM, provides a clear and evidence-based guideline for exercise prescription. The hybrid model of supervised and home-based sessions is also a valuable takeaway, offering a sustainable way to deliver effective therapy. By embracing this evidence and integrating PRT into our practice, we can empower our young patients to build strength, improve their mobility, and enhance their participation in daily life.