See A-Z of rehabilitation exercises
In case you cannot see the video, here is a still sequence -
Hip flexion and adduction exercises help to strengthen the hip muscles.
Relax on your back on a firm surface with your knees bent and a soccer ball held between them.
Holding the ball firmly - keeping the knees bent to 90 degrees - slowly bend the hip.
When you get the hip bent to 90 degrees, hold it there for a few seconds.
Slowly come back to the base position, repeating the sequence 10 times.