[A Pilot Investigation into the Effects of Extracorporeal Shock Waves on Muscular Dysfunction in Children with Spastic Movement Disorders]

Introduction: Extracorporeal shock waves (ESW) are being used increasingly frequently for the treatment of narrowly localized pain in the musculoskeletal system. Pain is normally associated with muscular dysfunction. Beginning with the observation that not only is the pain soothed by treatment with ESW, but that the muscular dysfunction itself is relieved, an attempt has been made to treat the impaired function in cases of infantile cerebral palsy with ESW.

Method: In 35 children and young people with mainly spastic disturbances of movement, the bellies of those muscles producing the flexion contracture of the lower limb were each treated with 500 non-focused pulses of low-energy ESW. The focus (focal pressure 10 MPA=0.06 mJ/mm) of the shock waves itself was placed either within the coupling cushion of the therapy source (Minilith, Storz Medical, CH-Kreuzlingen) or obliquely outside the patient's body. In this way ESW could be dispersed throughout the muscles and the risk of undesirable effects was minimized. The energy used amounted to about 30% of the threshold value at which cellular damage from focused treatment with ESW had been observed in the endothelium of the human umbilical cord.

Results: The degree of movement at the hip joint increased after one treatment by an average of 17 degrees, at the knee joint by 12.3 degrees and at the ankle joint by 7.1 degrees, each increase being statistically significant. Muscular stiffness, spastic co-contractions, and myofascial viscoelasticity, as well as dyskinetic and ataxic symptoms, decreased. It appeared as if a systemic action had entered into the motor control. Together with an increase in general proprioception, there was an improvement in body image, in economy of movement and also in the limbs that had not been treated. A few patients showed euphoric reactions for about 2 days after treatment. No undesirable effects were observed during a follow-up of 12 months. The treatment was painless and is therefore suitable for children. The biomechanical improvement remained for several weeks and this time could be used for initiating an improved pattern of movement.

Conclusion: ESW is suitable for use as an additional instrument for physiotherapeutic treatment of infantile cerebral palsy. The effective action of ESW on disturbed peripheral muscles has been discussed in terms of positive pressure and tensile wave forces and/or forces acting by cavitation. The results obtained in this pilot investigation showed particular a decrease in muscle stiffness. A controlled investigation with gait analysis and psychological control is to be undertaken.