Target Muscle/s: Rectus femoris (quadriceps), psoas, iliacus.
Sets & Reps: 3 x 30 seconds or 12 reps
Tempo: Isometric (hold for up to 30s), concentric (pull back for 1s, hold for 2s, return for 3s)
Frequency: Twice a week strength training program (or as advised if part of rehab plan)
As runners, we do tend to be somewhat obsessive creatures and a good example of this is our constant desire to stretch our hip flexors. This is not surprising as one quick Google search produces a multitude of articles and videos promoting the need for maximum hip extension and blaming many running related injuries on ‘tight hip flexors’ caused by ‘sitting down for too long’. Many therapists perpetuate this belief when you seek them for advice, so it may come as a surprise to you to hear that as far as hip extension goes (the distance your leg is able to travel behind you), research suggests that running really doesn’t require much more range than walking. In other words, if you can walk ok there’s probably no real need to worry about ‘tight hip flexors.’
Let’s take a quick look at what the hip flexors do: whilst standing on one leg, raise the other so your knee comes up to waist height. Hold it there off the ground and you will start feeling your hip flexor muscles getting tired, in particular the psoas, iliacus and rectus femoris (one of the quadriceps muscles in the thigh). These muscles have shortened (concentric contraction) to raise your knee high and are now working hard (isometric contraction) to hold that knee in the air. Now lower the leg back down as slowly as possible and feel these muscles controlling & decelerating the movement (eccentric contraction).
The actions above occur similarly when you are running: when your foot leaves the ground behind you, the hip flexors work concentrically to start pulling the leg through; they work isometrically to hold it in the air for a period of time and then work eccentrically to control your leg as the foot moves towards the ground. Once the foot lands, the hip flexors shorten again as you absorb ground impact, start to lengthen as your foot passes underneath you, reach maximum stretch (full hip extension) when the foot leaves the ground behind you, and so the cycle repeats. Much of the propulsion in running comes from this cycle with muscles and tendons storing energy while they lengthen and then using it for propulsion when they shorten.
Whether you are rehabbing a hip flexor injury or are looking for ways to strengthen your running form, for most runners it makes more sense to be strengthening the hip flexors rather than stretching them. It also makes sense to be preparing the muscles for the different types of contraction which they go through during the running cycle, i.e. concentric, isometric and eccentric. Choice of exercise will depend on current level of injury/pain/strength so be sure to first get assessed by a professional. The lying down resistance band hip flexion exercise is for many runners a good starting point, particularly if coming back from injury.
- ISOMETRIC: With one end of the resistant band attached to an immoveable object and the other end wrapped around the foot, pull the band back to around 90o and hold for up to 30 seconds. The exercise band needs to be tense enough to allow no more than 30 seconds. Once you get stronger and can do over 30 seconds you will need to use a tougher exercise band.
- ECCENTRIC: Use your arms each repetition to pull your leg back to start position and then slowly take 3 seconds to lengthen the leg (blue arrow). The exercise band needs to be tense enough to allow no more than 12 repetitions. Once you get stronger and can do over 12 repetitions you will need to use a tougher exercise band.
- CONCENTRIC: As above but do not use the arms. Take 1 second to pull the leg towards you (red arrow), hold still for 2 seconds then slowly release for 3 seconds (blue arrow). Once you get stronger and can do over 12 repetitions, you will need to find a tougher exercise band.
This exercise can be very useful when rehabbing a hip flexor injury. Your therapist may at first advise you to only perform the isometric version until you see strength gains. They may then progress you to the eccentric version, and finally the concentric version. Whatever version of exercise you are given, you always need to take the set to fatigue in order to stimulate strength gains. Bands are therefore coloured to signify level of resistance, normally from yellow (least resistance) to red, green, blue and finally black (highest resistance). You can also increase resistance by stretching the band more before engaging and by twisting it. Once sufficient strength gains have been seen, you may be progressed to other hip flexor strengthening exercises.
Matt Phillips is a Running Injury Specialist & Video Gait Analyst at StrideUK & Studio57clinic in Sussex. Follow Matt on Twitter: @sportinjurymatt