Exercise as it relates to Disease/Strength training in spastic cerebral palsy

Cerebral palsy (CP) is a physical disability developed in utero or shortly after birth that affects the movement and posture of those who carry it. One of the most recognisable symptoms of people with CP is muscular weakness. A study conducted in 1998 by D.Damiano and M.Abel set out to investigate how this issue can be treated, as (at the time of the study) little was done to clinically address muscular weakness in those with CP. This investigation focused on exploring how strength training could affect muscular weakness in those with CP and how it could be used in a clinical setting as a treatment for improving functional measures.

Where is the research from?
The study was carried out by researchers from the Department of Orthopedics at the University of Virginia Health Sciences Center, USA. The testing was conducted in a Pediatric rehabilitation center at a tertiary care hospital.

Funding was supplied by a grant from the Research and Development Committee at the University of Virginia Health Sciences Center. The paper was published in the peer-reviewed journal Archives of Physical Medicine and Rehabilitation in February 1998.

What kind of research was this?
This study was a prospective before and after trial investigating the effectiveness of a six week strength training program in children with spastic CP. The information gathered can be further applied to the treatment of those with the condition alongside other clinical implementations.

What did the research involve?
This study set out to investigate the clinical effectiveness of strength training in children with spastic CP in relation to increasing muscle strength and improving motor function. Eleven children between six and twelve years of age took part in a six week strength training program, six of which suffered from spastic diplegia (paralysis of like parts on both sides of the body) and five suffered from spastic hemiplegia (paralysis on one side of the body). Before the training commenced, researchers performed an isometric strength test of eight selected muscle groups to measure baseline strength before the program intervention begun. A gait analysis took place to investigate the functional walking capacities of the subjects, alongside an energy expenditure analysis during the gait to calculate walking efficiency. A Gross Motor Function Measure (GMFM) was also completed, which involves performing a series of activities to compare the motor function of an individual over five dimensions to a normally developed child of their age. The same tests were undertaken post-study and results were recorded.

Each strength training program was individually assigned in consideration of the results obtained from the pre-testing. The weakest muscle groups in those with diplegia and the most asymmetrical muscle groups in those with hemiplegia were trained three times per week over the six week period. Each muscle group was trained with an exercise in four sets of five reps at approximately 65% of the recorded maximum isometric strength for that muscle group. Strength was measured every two weeks and the weight of each exercise was changed in proportion to the recorded strength gains.

What were the basic results?
The results observed an increase in muscular strength in the trained muscles, with those in the diplegia group experiencing a 69% increase in muscle strength and those in the hemiplegia group showing a 20.3% improvement on their weaker side. No increase was observed in untrained muscles, suggesting that the increases in strength were due to the training interventions.

An increase of 15.6% in gait velocity was also noted due to an increased cadence and significantly better scores in one of the five dimensions of the GMFM test was noted by an 11% improvement. Both of these results reflect the improvements in motor function due to the strength training program intervention.

Mean walking efficiency showed no significant change, however those with higher increases in velocity showed poorer efficiency while those with minimal walking velocity improvements showed improved efficiency.

How did the researchers interpret the results?
It was concluded by the researchers that "Short-term strength training programs demonstrate positive functional outcomes for children with spastic CP across diagnostic categories and a wide spectrum of involvement in the ambulatory population."

In Conclusion
This paper was an addition to the growing pile of evidence of its time suggesting that strength training is effective in clinically treating CP by improving muscle strength. The muscles that were trained by the researchers showed an increase in strength that the untrained muscles did not see. The improvements in functional parameters noted by the study further suggest the effectiveness strength training has on the treatment of the condition.

Some limitations to this study include that the training intervention was only short term and that non-ambulatory CP sufferers were not included, however other research has suggested strength improvements in both these settings.

Increases in muscle strength lead to enhanced functional capacity of the muscles worked, leading to improved performance of activities of daily living. Research in this area has continued to progress, with many studies continuing to suggest that strength training is a beneficial and safe way to combat muscular weakness and improve functional capacity in those with CP which neatly backs up the information gathered from this study.

Implications
It appears clear from this study and others in its field that strength training could be an important part of improving the physical abilities and quality of life in those effected with spastic CP. Incorporating well monitored strength training alongside other clinical treatments in to the routine of a person suffering from CP would appear very beneficial in the management of the condition.