Table 4. Intervention: exercises

Exercise	Instruction	Purpose	Frequency	Repetitions
Quadruped rock back	On hands and knees, pull in the abs and rock back toward heels	To improve hip flexion and femoral head posterior glide	2 times per week	5 minHold for 5 s, rest for 5 s
Side-lying hip abduction and ER	Pull in the abs.Move in the hip joint onlyDo not let the pelvis rotateAlternately for both sides	To strengthen the hip abductor and external rotators	2 times per week	10 minHold for 10 s, rest for 5 s
Prone hip extension	Pull in the abs.Do not allow GT anterior displacementAlternately for both sides	To strengthen the gluteus maximus	2 times per week	10 minHold for 10 s, rest for 5 s
Sitting knee extension	Pull in the abs.Move in the knee joint onlyDo not allow the pelvis to posteriorly rotateAlternately for both sides	To elongate the hamstring	2 times per week	10 minHold for 10 s, rest for 5 s

Abbreviations: ER, external rotation; abs, abdominals; GT, great trochanter.