Hip flexor strength is vital for optimal performance in sprinting and jumping. Many athletes neglect hip flexor strengthening exercises in their training programs. During sprinting your hip flexor muscles assist in the recovery phase, when you bring your leg up and forward. These muscles are major contributors to stride frequency. Strong hip flexors are necessary for rotating the hip quickly to a flexed position and to prepare the foot for ground contact. Which can make a huge difference in a athletes top end speed.
The hip flexor muscles are also highly involved during the counter movement prior to jumping. The counter movement is a spring or coiling action, making it very important for a high jump. Try to jump as high as you can by just keeping your legs straight and then bend and try to jump and you will see and feel the difference.
Here is one exercise that can improve hip flexor strength:
Wall drive with resistance holds (using thera bands) 3x 10-15 seconds holds each side
Lean on the wall at a 45 degree angle having arms shoulder width apart and shoulder height
Place the thera band around the front of your feet
Tighten your core and glute
Big toe up to the top of your shoe and maintain the whole time
Try to maintain knee height with hip height
Drive one knee up without bending your back and hold for 10-15 seconds then switch
Repeat 3x’s each side