Lie on the ground with the stability ball
under your heels with your legs straight and your toes pointing up. Engage your inner core muscles below the belly
button. Then extend your hips by squeezing your butt
and lifting it off the ground. Then bring the ball in towards you by flexing
your knees and hold for a second and then straighten your legs back to the start position
while keeping your butt up and hips extended. Keep your inner core engaged the entire time. Start by doing 3 sets of 10 repetitions and
then progressing it to 3 sets of 15 to 20 repetition 4 times per week. This is great for strengthening the hamstring
muscles along with your glutes and core stability muscles to help protect your ACL knee ligament.