[estherderu]

dear Spandanphysio,

According to Crenna 1998 & Perry 1992 & Gage 1991 quoted in Motor Control 3rd edition authors: Anne Shumway & Marjorie Woollacott, " it was originally thought that hamstrings overactivity was the result of spasticity. Research has found that after selective dorsal rhizotomy ( sensory nerve roots ), hamstring overactivity had not decreased in children with cerebral palsy. This suggests that the basis for hamstring overactivity is abnormal coordination, not a simple hyperactive reflex.

Crouched gait pattern results from excessive hip and knee flexion in conjunction with excessive ankle plantar flexion and anterior pelic tilt during the stance and swing fase of gait.
Of course ,static or dynamic contractions can limit range of motion in these joints as well.
This flexed position requires additional muscle activity for stability. Waters 1992"

Much more information in this recommendable book.

kind regards
Esther de Ru