Effect of Whole Body Vibration Therapy on Muscle Function, Gross Motor Function and Bone Mineral Density in Children With Spinal Muscular Atrophy - a Feasibility Study
Phase: NA
Conditions: Spinal Muscular Atrophy Type 3
Sponsor: The Hong Kong Polytechnic University

Effect of Whole Body Vibration Therapy on Muscle Function, Gross Motor Function and 
Bone Mineral Density in Children with Spinal Muscular Atrophy - a Feasibility Study 
 
 
NCT number: NCT03056144 
Document date: August 1, 2018 
 
 
 

Effect of Whole Body Vibration Therapy on Muscle Function, Gross Motor Function and 
Bone Mineral Density in Children with Spinal Muscular Atrophy - a Feasibility Study 
 
Abstract 
Spinal muscular atrophy (SMA) are one of the common physical disabilities in childhood. For 
SMA, progressive muscle weakness and early fatigue hamper the mobility of the sufferers. 
Osteopenia is common for this population group due to poor bone growth and muscle disuse. 
As a result, non-traumatic related fractures and bone pain are common. Recently, whole body 
vibration therapy (WBVT) has been proven to improve bone health and muscle function in 
healthy adults and post-menopausal women. Among the limited studies on the WBVT for 
children with muscular dystrophies, promising results have been shown on gross motor 
function, balance, and muscle strength and the WBVT appears to be safe for children with 
SMA. 
 
The present pilot study is designed to investigate if WBVT is safe and feasible for individuals 
with SMA and if WBVT can improve muscle function, functional abilities, postural control 
and bone mineral density in children with SMA. Convenience samples of 10 individuals with 
SMA type III will be recruited. The participants will receive the WBVT of 25 Hertz and a peak-
to-peak amplitude of 4mm for a session of about 18 minutes, 3 days per week for 4 weeks. 
Assessment will be performed at the baseline and the completion of the intervention to examine 
the muscle function, functional abilities, postural control and bone mineral density of the 
participants. 
 
It is anticipated that the outcomes of this pilot study for SMA may show if this intervention is 
safe, feasible and beneficial for children with SMA type III regarding to muscle function, 
functional abilities, postural control and bone mineral content and if there may be any related 
practical issues of this intervention to this population group. The outcomes also provide 
research evidence to clinicians if this intervention should be recommended to individuals of 
similar problems. 
 
Objectives 
The objective of the present pilot study is to investigate if the WBVT is able to improve the 
muscle strength, functional abilities, postural control, and bone mineral density in children/ 
adolescents with SMA type III. 
 
Null hypotheses to be tested: 
1. That there is no statistically significant difference in gross motor function as measured 
using the North Star Ambulatory Assessment (NSAA) pre- and post-intervention. 
2. That there is no statistically significant difference in functional abilities as measured using 
Pediatric Evaluation of Disability Inventory (PEDI) pre- and post-intervention. 
3. That there is no statistically significant difference in postural control as measured using 
Segmental Assessment of Trunk Control (SATCo) pre- and post-intervention 
4. That there is no statistically significant difference in sub-maximal exercise capacity as 
measured using the 2-minute walk test (2MWT) pre- and post-intervention. 
5. That there is no statistically significant difference in body composition and bone mineral 
density as measured using dual X-ray absorptiometry (DXA) pre- and post-intervention. 
 
 
Methodology 
This feasibility study aims to examine the safety of the WBVT on children with type III SMA. 

Children with type III SMA are targeted as they have adequate independence living in the 
community but still experience early fatigue during normal level of exercises due to the nature 
of their condition. They are at high risk of suffering from complications due to compromised 
mobility such as osteopenia, early loss of ambulation when compared with their healthy peers. 
 
Intervention protocol 
The WBVT will be performed on the GalileoTM Med L Plus (Novotech Medical GmbH) with 
the study participants standing with both knees flexed at least 20 degrees. The vibration 
frequency and duration will be increased over 5 days to the maximum of 3 minutes of 24 to 25 
Hz with a peak to peak amplitude of 4mm. The participants of the intervention group will 
undergo the WBVT 1 session per day, 3 days per week for 4 weeks. The whole WBVT session 
will last 18 minutes with 9 minutes of vibration. This intervention regime is based on the 
recommended dosage to improve bone mineral density in children with physical disabilities in 
a systematic review on previous relevant literature (Matute-Llorente et al 2014). The 
intervention regime is as follows: 
 
Day 
Vibration 1 
Rest 1 Vibration 2 
Rest 2 Vibration 3 
Rest 3 
1st 
1 min; 12Hz 
3 min 
1 min; 12Hz 
3 min 
1 min; 15Hz 
3 min 
2nd 
1 min; 15Hz 
3 min 
1 min; 15Hz 
3 min 
2 min; 15Hz 
3 min 
3th 
2 min; 15Hz 
3 min 
3 min; 15Hz 
3 min 
3 min; 15Hz 
3 min 
4th  
2 min; 24-25Hz 
3 min 
2 min; 24-25Hz 
3 min 
2 min; 24-25Hz 
3 min 
>5th 
3 min; 24-25Hz 
3 min 
3 min; 24-25Hz 
3 min 
3 min; 24-25Hz 
3 min 
 
The participants will perform mini-squats (knee flexion from 20 to 40 degrees) during 
Vibrations 1 and 3 and weight-shifting between right and left legs during Vibration 2 on the 
vibration platform under the supervision of a research assistant, who will be trained by the PI 
prior to the commencement of the study. All treatment sessions will be conducted at the Hong 
Kong Polytechnic University Rehabilitation Clinic as most of children and adolescents with 
SMA study in main-stream schools in Hong Kong. 
 
 
Participants: 
10 children with type III SMA aged from 6 to 18 years will be recruited. The age range is 
extended aiming to increase the number of recruitment due to the rarity of the condition. All 
participants will continue their usual intervention regime, if any, during the study period. They 
are strongly encouraged not to participate any activities that may involve any total body 
vibration during the study period. 
 
Inclusion criteria: 
To be included in the study, children must: 
1. Be able to stand on the vibration platform without support; 
2. Be able to undertake clinical examination and DXA evaluation; and 
3. Informed consent by the participant’s parent/ guardian. 
 
Exclusion criteria: 
1. There is a history of fracture within 8 weeks of enrolment of the present study and acute 
thrombosis, muscle or tendon inflammation, renal stones, discopathy or arthritis as reported by 

their parent/ guardian. 
2. There is a history of using any of the following medications, regardless of dose, for at least 
1 month, within 3 months of enrolment into the present study: anabolic agents or growth 
hormone.  
 
Outcome measures: 
Assessments will be performed at baseline and after 4 weeks of the intervention. All outcome 
measures will be conducted on all study children, unless specified to children with specific 
diagnoses. They include: 
1. Muscle strength 
a) hand-held dynamometer will be used to measure muscle strength in hip flexors, hip 
extensors, hip abductors, knee extensors, knee flexors, ankle plantarflexors and 
dorsiflexors in standardised muscle testing positions (Clarkson and Gilewich 2000). 
Muscle strength will be reported in kilograms. 
2. Functional abilities 
a) North Star Ambulatory Assessment (NSAA) will be used to examine the gross motor 
function of the participants (Mayhew et al 2011, Scott et al 2012). 
b) 2-minute walk test (2MWT) will be used to assess submaximal exercise capacity (Pin 
2014, Pin and Choi 2016). Distance covered in 2MWT will be measured by a distance-
measuring trundle wheel in metres. 
c) Range of movements in hip flexion, extension and abduction, knee flexion and 
extensions and ankle dorsiflexion and plantarflexion will be measured in standardised 
positions (Clarkson and Gilewich 2000). 
d) Segmental Assessment of Trunk Control (SATCo) to assess the segment trunk control 
(Butler et al 2010). 
e) Pediatric Evaluation of Disability Inventory (PEDI) (Haley et al 1992) to assess 
functional capacities in the domains of daily activities, mobility and social/cognitive 
function. A validated Chinese version will be used (Chen et al 2009). 
3. Bone mineral density 
a) 
Dual Energy X-ray Absorptiometry (DXA)- bone mineral content (BMC) and areal 
bone mineral density (aBMD) of the distal femur and total body will be measured. 
Only if it is not feasible to obtain the BMC and aBMD of the femur, BMD of the 
lumbar spine will be used. The effective radiation dose for these DXA studies will 
be <2 microSv, which is a very minimal dose of radiation (Houlihan and Stevenson 
2009). All participants will have DXA done in a private service as bone density 
examination is not routine for the children with motor disabilities in Hong Kong. 
b) 
Anthropometry at baseline and 4 weeks including standing height and weight. Body 
mass index (BMI) will be calculated and converted into a z-score. 
4. Parental satisfaction 
a) Parental/ participant questionnaire to record present medications of their children, 
satisfaction or comments on the intervention regime by children/ parents of the 
intervention group. 
b) Visual analogue scale of 0 to 10, in which 0 means no pain and 10 as extreme pain to 
assess pain or discomfort at rest and if any, pain or discomfort associated with the 
intervention as reported by the children and/or parents. 
c) A log of compliance and comments during the intervention. 
 
Statistical analysis plan 
Due to the small sample size, non-parametric tests will be used to analyse the results. All results 
will be reported in means and standard deviations. Wilcoxon Signed test will be used to 

compare all the outcome measures listed above (no. 1 to 3) before and after the intervention. 
Results of outcome measure no. 4 listed above will be reported in descriptive terms for the 
comments from the parents and/or from the participants and compliance/ comments during the 
intervention and Wilcoxon Signed test will also be used to compared the visual analogue score 
of discomfort before and after the intervention.