widely accepted test for measuring the muscular activation pattern in the lumbo-pelvic area [4]. The importance of PHE is that the muscle activity pattern during this movement has been heorized to simulate those used during functional movement patterns such as gait [5,6]. It is thought that changes in this pattern can decrease the stability of lumbo-pelvic region during walking [12]. Good reliability has been reported for PHE in detecting deviation of lumbar spine from the midline
[13].