Effects of Barefoot vs. Shod Whole Body Vibration Training in Children With Cerebral Palsy

Cerebral palsy (CP) refers to a group of lifelong conditions that affect the development of movement and coordination that lead to activity limitations due to damage to the developing fetal or neonatal brain tissue. Although the brain lesion is static, it can lead to progressive musculoskeletal system problems. As a result of the restriction of ankle joint range of motion and many microscopic changes in the muscle structure, plantar pressure distribution is impaired in children with CP which brings about gait and balance problems. Moreover, since physical activity may be restricted due to spasticity, poor motor control, muscle weakness and balance problems; the main goals in CP rehabilitation are normalization of muscle tone, improving walking function by increasing joint range of motion, strength and balance and consequently improving mobility.

There is a need for adjunctive treatment methods with low side effect profiles that can be applied in the long term to prevent musculoskeletal complications and preserve existing functions in children with CP. Whole body vibration training (WBVT), is a therapeutic exercise method that is growing in popularity due to its ease of application, low side effect profile and non-invasiveness as an auxiliary treatment method to traditional rehabilitation programs. Although WBVT is suggested as an easily applicable and safe treatment method with home-type vibration devices; scientific evidence is still lacking and it has not yet been included in routine rehabilitation programs due to the small number of high-quality randomized controlled trials. This study aims to determine the efficacy of barefoot vs. shod WBVT in addition to the conventional physiotherapy, compared to the conventional physiotherapy alone, in children with mild-moderate CP on pedobarographic evaluation, balance, endurance and lower extremity functions. As a result of this study, it might possible to offer children with CP an accessible, safe and helpful treatment method with established protocols.

CP describes a group of neurological disorders that occur after damage to the brain during development. Although brain damage is non-progressive; spasticity, poor motor control, muscle weakness and balance problems are frequently observed due to first motor neuron damage. Restriction of physical activity causes joint contractures and bone deformities, which negatively affect muscle strength and motor function. The main goals in CP treatment are to normalize muscle tone, reduce joint stiffness, increase joint range of motion, strength and balance.

In children with CP, while proximal motor function of the lower extremities is generally preserved; calf muscles, which are well-known to greatly influence postural control, are particularly affected by primary impairments such as spasticity, selective motor control deficits and weakness. As gastrocnemius muscle stiffness increases with growth, it undergoes shortening and atrophy; while its antagonist muscle, the tibialis anterior, often becomes weak. In later ages, ankle joint of motion progressively decreases, accompanied by numerous microscopic changes in muscle structure leading to plantar flexion contractures in children with CP. This results in abnormal plantar pressure distribution, contributing to gait and balance problems. Increased plantar flexor activity or knee flexion increases load on the forefoot. Significant differences have been reported in weight distribution on the feet of children with hemiplegic CP. Previous studies suggest that children with CP exhibit distinct plantar pressure patterns.

WBVT is an emerging therapeutic exercise method in addition to traditional rehabilitation, gaining popularity due to its ease of application and low side effect profile. In WBVT, vibration motion generated by the platform stimulates a movement pattern similar to human gait which results in activation of proprioceptive spinal circuits, leading to compensatory rhythmic muscle contractions in the lower extremities and trunk. Studies conducted on adult, adolescent and pediatric individuals with CP report positive effects of WBVT on gross motor function, balance, muscle strength, muscle tone, spasticity, proprioceptive perception, functional activities and walking. In brief, WBVT stands out as a safe, non-pharmacological method to increase muscle mass in specific pediatric populations.

Enhancing balance and lower extremity function is crucial for improving mobilization, a key goal in CP treatment. CP is commonly approached as a pediatric issue, but approximately 90% of individuals with CP reach adulthood and their life expectancy is similar to that of general population. Given that CP is a lifelong condition, there is a need for adjunctive therapies with low side effect profiles that can be applied in the long term to prevent complications and preserve existing functions. WBVT emerges as a promising adjunctive therapy for inclusion in rehabilitation programs for CP. It is non-invasive, easy to administer and has low side effect profile. WBVT can be applied quickly and conveniently with home-based devices, making it a practical treatment option.

Not only is the number of randomized controlled trials limited, but existing studies also have shortcomings such as a lack of specification regarding footwear (shoes/socks/barefoot/assistive devices) used during WBVT, as well as addressing technical terms (frequency, peak-to-peak displacement, amplitude, etc.), type of vibration (side alternating/synchronous), and the types of exercises (static or dynamic) performed on the platform.

In this study, participants will be selected from children diagnosed with CP who are followed up at the pediatric rehabilitation clinic of Trakya University Department of Physical Medicine and Rehabilitation and who meet the inclusion and exclusion criteria. Participants will be randomized into 3 groups at the beginning of the study. Age, gender, more affected extremity, use of orthoses/assistive devices, Gross Motor Function Classification System (GMFCS) level, history of orthopedic surgery and presence of comorbidities will be recorded for all participants. Written informed consent will be obtained from the families of all participants.

Group 1 will receive sham WBVT in addition to conventional physical therapy program. Groups 2 and 3 will receive WBVT with footwear and barefoot, respectively in addition to conventional physical therapy program. This study aims to determine the efficacy of barefoot vs. shod WBVT in addition to the conventional physiotherapy, compared to the conventional physiotherapy alone, in children with mild-moderate CP on pedobarographic evaluation, balance, endurance and lower extremity functions. By addressing the gaps in the literature and establishing the effects of WBVT, it is anticipated that WBVT will contribute to improving mobility, balance and overall quality of life for children with CP. Detailed protocol presentation in this study will contribute to pediatric rehabilitation in clinical practice and shed light on future research.

Eligibility Criteria:
Inclusion Criteria:

1. Between ages of 3 and 18
2. Diagnosed with CP
3. Able to walk at least 10 meters with or without assistive devices
4. GMFCS level 1-3
5. Able to stand independently or with self-support on a vibration platform for 3 minutes
6. Able to understand verbal commands and cooperate during clinical examination

Exclusion Criteria:

1. History of lower extremity botulinum toxin injection or surgery in the past 6 months
2. Any bone fracture in the past 8 weeks
3. Acute thrombosis, muscle-tendon inflammation, nephrolithiasis
4. Presence of implants in the spine or lower extremities
5. Pregnancy
6. Presence of mental impairment, visual or hearing loss affecting balance
7. History of seizures in the past 6 months
8. ASH 4 spasticity/contracture in any lower extremity muscle group
9. Presence of cardiovascular or pulmonary disease
10. Diagnosis of dyskinetic cerebral palsy