1. Functional and Applied Biomechanics Section; Rehabilitation Medicine Department; National Institutes of Health; Bethesda Maryland
2. Rehabilitation Medicine Department; University Hospital of Brest; Brest France
3. LaTIM, INSERM U1101 Brest; France
4. Department of Physical Medicine and Rehabilitation; Mayo Clinic; Rochester Minnesota 55905
5. Mt Washington Pediatric Hospital; Baltimore Maryland