The role for hip surveillance in children with cerebral palsy

Spastic hip displacement is the second most common deformity seen in children with cerebral palsy (CP), and the long-term effects can be debilitating. Progressive hip displacement leading to dislocation can result in severe pain as well as impaired function and quality of life. Recent population-based studies have demonstrated that a child’s Gross Motor Functional Classification System (GMFCS) level is most predictive for identifying hips “at-risk” for progressive lateral displacement. As a result, in many developed countries, hip surveillance has now been adopted as an integral piece of the comprehensive care puzzle for the management of children with spastic hip displacement. This paper reviews the spectrum of treatments available for progressive hip displacement, examines the current literature on the success of hip surveillance, and illustrates an example of a current hip surveillance program stratified by the GMFCS level.     

Neuromuscular factors determining 5 km running performance and running economy in well-trained athletes

This study investigated the effects of the neuromuscular and force–velocity characteristics in distance running performance and running economy. Eighteen well-trained male distance runners performed five different tests: 20 m maximal sprint, running economy at the velocity of 4.28 m s⁻¹, 5 km time trial, maximal anaerobic running test (MART), and a treadmill test to determine VO_2max. The AEMG ratio was calculated by the sum average EMG (AEMG) of the five lower extremity muscles during the 5 km divided by the sum AEMG of the same muscles during the maximal 20 m sprinting. The runners’ capacity to produce power above VO_2max (MART VO_2gain) was calculated by subtracting VO_2max from the oxygen demand of the maximal velocity in the MART (V _MART). Velocity of 5 km (V _5K) correlated with V _MART (r=0.77, p<0.001) and VO_2max (r=0.49, p<0.05). Multiple linear regression analysis showed that MART VO_2gain and VO_2max explained 73% of the variation in V _5K. A significant relationship also existed between running economy and MART VO_2gain (r=0.73, p<0.01). A significant correlation existed between V _5K and AEMG ratio during the ground contact phase at the 3 km (r=0.60, p<0.05) suggesting that neural input may affect distance running performance. The results of the present study support the idea that distance running performance and running economy are related to neuromuscular capacity to produce force and that the V _MART can be used as a determinant of distance-running performance.