Background: Gait cycle and pressure distribution patterns can now be recorded quite simply and reproducibly with inexpensive in-sole pressure recorders. However, it is not known whether such readings are sufficiently stable to provide useful information in monitoring children with spastic hemiplegic cerebral palsy (HCP).
Objective: The aim of this study was to asses the reproducibility of gait cycle and plantar pressure in HCP.
Methods: Fourteen children with HCP (Gross Motor Function Classification System level I or II) undertook two walking trials (4 × 12 meters at self-selected speeds) with a one-week inter-test interval. Spatio-temporal gait cycle parameters and peak plantar pressures were measured at each visit, using Parotec in-shoe pressure sensors.
Results: In the unaffected limb, satisfactory reproducibility was found for measurements of velocity, step frequency, time of double support, and step duration, but not for step amplitude or contact time. However, in the affected limb, only velocity and step duration showed moderate reproducibility. Likewise, all of 8 pressure measurements were reproducible for the unaffected limb, but pressures for the affected limb were only consistent at 4 sites (metatarsals 4-5, lateral heel, lateral mid-foot and hallux).
Conclusions: Since plantar pressures are unstable only in the affected limb, the cause of variation is likely immediate spasm during movement of this limb rather than a more permanent change of posture. Some spatio-temporal parameters and plantar pressure readings have sufficient stability in both unaffected and affected limbs to allow their use when evaluating gait and planning therapy for children with HCP.
Keywords: Bland-Altman tests; children; gait cycle; hemiplegic cerebral palsy; peak plantar pressures; rehabilitation.