Estimation of vastus medialis' excitability in cases of lateral patellar instability in children.
BACKGROUND
The aim of this study was to evaluate the excitability of the vastus medialis muscle in children with lateral patellar instability, because it is assumed that, apart from restoring the elasticity of passive lateral restraints, the main goal of rehabilitation of this dysfunction is strengthening of the vastus medialis.


METHODS
Measurements were done in 56 patients (mean age 15.9 years) in the study group and 38 patients (mean age 15.2 years) in the control group. The study was carried out from October 2006 to April 2007. Neuro-muscular-excitability was assessed by determining rheobase. A Sonopuls 992 apparatus was used for this purpose.


RESULTS
72 measurements were taken in the study group, with a mean value of rheobase of 15.3 mA(+/-4.9). In the control group, 76 measurements were taken and the mean value of rheobase was 11.5 mA(+/-4.1).


CONCLUSIONS
1. Vastus medialis muscles in children with lateral patellar instability display significantly higher mean values of rheobase in comparison to mean values from the control group, i.e they are less excitable. Consequently, measuring rheobase in the vastus medialis in children with lateral patellar instability is an objective method for the assessment of treatment and rehabilitation outcomes. 2. Strengthening the vastus medialis muscle, the only active medial stabilizer of patella, is one of the most important elements of rehabilitation in children with signs of lateral patellar instability because it has lower excitability in these children than in healthy children.
Kaczmarek
Kinga
K
ENEL MED Medical Center, Warszawa, Poland.
Wysokińska
Aleksandra
A
Zytkowski
Andrzej
A
D000293:Adolescent; D000328:Adult; D002648:Child; D004599:Electric Stimulation Therapy; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000503:physiopathology* / Q000534:rehabilitation* / Q000601:surgery; D008297:Male; D010329:Patella / Q000503:physiopathology; D052097:Quadriceps Muscle / Q000503:physiopathology*; D055815:Young Adult