drawings of muscles and exercise apparatus

Saturday, February 11, 2006

Hip flexors - the most underdeveloped muscle group in strength training

[Summary: Strong hip flexors provide an advantage in a wide range of sports and athletic activities but they are the most neglected muscle group in strength training. The problem in developing hip flexor strength has been the lack of appropriate exercises, but the development of flexor-specific apparatus offers great potential for fully developing these muscles.]

Despite their importance to a wide range of athletic and sporting activities, the hip flexors are the most neglected major muscle group in strength training. It is very rare to find training programs that include hip flexor exercises. By contrast there is usually a great deal of emphasis on exercises for the leg extensors.

Drawing of iliopsoas muscle group

There are some obvious reasons for this comparative neglect. The principal muscles involved in hip flexion are the psoas and the iliacus, collectively known as the iliopsoas. Because they are relatively deep-seated rather than surface muscles they may have been overlooked by bodybuilders who have traditionally been the major innovators in strength training. Secondly, there are no obvious ways to adequately exercise them with free weights. Finally, these muscles do not have the obvious functional importance of their extensor counterparts. Yet, as antagonists, both hip and knee flexors perform a vital role in controlling the rate of descent and ascent in leg extension exercises such as the squat.

There is no corresponding problem of underdevelopment with the muscles responsible for knee joint flexion, the hamstring group. Because they cross two joints they are active in both leg extension and leg flexion. They act to flex the knee joint and also to extend the hip joint. Therefore they tend to be strengthened by complex leg extension exercises. Also hamstrings can be developed and strengthened through the use of the leg curl apparatus.

Strong hip flexors provide an advantage in a wide range of sports and athletic activities. In sprinting high knee lift is associated with increased stride length and therefore considerable attention is given to exercising the hip flexors. However, they are usually not exercised against resistance and consequently there is unlikely to be any appreciable strength increase.

Hip flexor strength is directly relevant to a range of activities in football. Kicking a ball is a complex coordinated action involving simultaneous knee extension and hip flexion, so developing a more powerful kick requires exercises applicable to these muscle groups. Strong hip flexors can also be very advantageous in the tackle situation in American football and both rugby union and rugby league where a player is attempting to take further steps forward with an opposing player clinging to his legs.

In addition those players in American football and rugby who have massively developed quadriceps and gluteus muscles are often unable to generate rapid knee lift and hence tend to shuffle around the field. Having stronger flexors would significantly improve their mobility.

It is commonly asserted that marked strength disparity between hip extensors and hip flexors may be a contributing factor in hamstring injuries in footballers. It is interesting to speculate on whether hip extensor/flexor imbalance might also be associated with the relatively high incidence of groin injuries.

Other sports where increased iliopsoas strength would appear to offer benefits include cycling, rowing and mountain climbing, in particular when scaling rock faces.

The problem in developing hip flexor strength has been the lack of appropriate exercises. Two that have traditionally been used for this muscle group are incline sit-ups and hanging leg raises, but in both cases the resistance is basically provided by the exerciser's own body weight. As a consequence these exercises can make only a very limited contribution to actually strengthening the flexors.

Until now the only weighted resistance equipment employed for this purpose has been the multi-hip type machine. When using this multi-function apparatus for hip flexion the exerciser pushes with the lower thigh against a padded roller which swings in an arc. One difficulty with this apparatus is that the position of the hip joint is not fixed and thus it is difficult to maintain correct form when using heavy weights or lifting the thigh above the horizontal.

With the release of the MyoQuip HipneeFlex there is now a machine specifically designed to develop and strengthen the leg flexors. It exercises both hip and knee flexors simultaneously from full extension to full flexion. Because the biomechanical efficiency of these joints decreases in moving from extension to flexion, the mechanism is configured to provide decreasing resistance throughout the exercise movement and thus appropriate loading to both sets of flexors.

The absence until now of effective techniques for developing the hip flexors means that we do not really know what benefits would flow from their full development. However, given that in elite sport comparatively minor performance improvements can translate into contest supremacy, it is an area that offers great potential.

(See also my follow-up postMyoQuip launches the HipneeFlex - hip and knee flexor strength builder.)

6 comments:

Nick said...

Great post Bruce, another form of exercise that could work the hip flexors and knee flexors would be to tie weights to your feet and then from a hanging position pull your knees to your chest. This would have a primary disadvantage in that holding weights between the legs, normally dumbbells, is awkward. Your machine is great.

I have read a number of articles that stress that hip flexor strength is essential to athletic function simply because the body will begin to retard the agonist action early if the antagonist is weak. This reaction of the body prevents injury by preventing over extension. Strong antagonists allow the agonist to fire for much longer before the antagonist must fire to prevent joint over extension. The early retardation will slow the movement restrict range of motion and will cause slower runners. If the Weyland study is correct in its assertion that overall speed is dependant on ground forces generated and range of motion (as these two functions increase stride length) and not leg speed then by deduction if cycle times remain constant but stride length increase then speed must increase, in my opinion. So this type of exercising should have a positive effect on both leg drive in contact and overall speed and should see a reduction in overall injuries.

For vertical jump testing people often stretch the hip flexors to reduce their activation during the jump process as this is supposed to help vertical jump, however if the hip flexor is strong it may remain unactivated for longer also helping the vertical jump. This HipKnee flex machine in conjunction with a hip extension exercise like the ScrumTruck will ensure that strong hip flexors are kept both strong and lengthened to the correct range of motion. This will ensure that extension is not reduced because of overly tight hip flexors, as a combination these two machines could add enormously to overall performance. Looking forward to seeing results from this machine.

Bruce Ross said...

Just to reinforce the point about the iliopsoas being deepseated rather than surface muscles, I cam across an interesting snippet on the Fire Fighters Workout site:

"To get a sense of where your hip flexors are and what they do, place your hand over the junction between the pelvis and either thigh. Now raise one foot off the floor an inch or two. As you do, the hip joint will bend, and you'll feel the powerful hip flexors contract."

panthers8 said...

I am a football player who strained hs hip flexor this season. I went through therapy and noticed an improvement. After reading this blog I noticed that it was talking directly to me. I always shuffle around the field and cannot reach my maximum speed. If anybody knows of any good hip flexor exercies please e-mail me at hattrickmatt2@sbcglobal.net, it will be greatly appreciated.

sebastian eubank said...

i am a rugby and american football player; i also strained my hip flexor one day at practice just by running. I spent a whole load of money on an MRI scan and x-ray and therapy because no doctor could pin-point the problem. They finally found out my hip flexor had been strained. I went to physical therapy for 3 weeks and it largely improved. Although sometimes i still feel a discomfort in it. This is why i am trying hard to find the best exercises and stretches for it. If you have any info for me my email address is seb_banks@hotmail.co.uk
i know this would be a little out of your way but would be deeply appreciated.
thank you.

sebastian eubank said...

i am a rugby and american football player; i also strained my hip flexor one day at practice just by running. I spent a whole load of money on an MRI scan and x-ray and therapy because no doctor could pin-point the problem. They finally found out my hip flexor had been strained. I went to physical therapy for 3 weeks and it largely improved. Although sometimes i still feel a discomfort in it. This is why i am trying hard to find the best exercises and stretches for it. If you have any info for me my email address is seb_banks@hotmail.co.uk
i know this would be a little out of your way but would be deeply appreciated.
thank you.

Shane said...

Hi a couple weeks ago I pulled both my hip flexors in high jump
My main event is sprinting but on the sidelines i do long jump and high jump because people say i have an incredible verticle (i can hurdle 140cm)When i pulled my hip flexors the bar was set at 166cm and it was raining. I could barely walk let alone run and i was stupid enough to go to another track meet and most likely injure them further. I have seen a physiotherapist twice and have been icing my hips. However last night I tried to run 60 metres full tilt with spikes on and after stopping they started hurting. I have a major championship meet in 2 and a half weeks and i need some ideas on how to strengthen and heal my hip flexors so i am able to go. please help--Shane