The Importance of Internal Rotation

Pretty much everyone has now grasped the importance of hip mobility, but are we going about assessing and addressing it in the right way? A huge amount of emphasis has been placed on the role of restrictions in the hip flexors, justifiably in the large majority of the population, but deficits in internal rotation (IR) are often overlooked. In this article we’ll outline why IR is so important.

Why Is Internal Rotation Important?

Normal kinematics of the leg require the femur to internally rotate within the hip capsule. IR is necessary to some degree to be able to walk, run, squat and perform pretty much every functional movement you can think of. Given that running or jumping movements, the basis of the majority of sports, require only a limited range of motion, a hip internal rotation deficit (HIRD) is not always noticeable. Where a HIRD does become a problem is during movements that require either deep hip flexion or trunk rotation; these articulations require a significant amount of IR to be performed correctly. If the body doesn’t have the necessary IR to complete the movement then other structures in the body are forced to compensate. Ideally, we’re looking for athletes to have about 45o of IR although the majority can cope with around 35o.

Joint Centration

Joint centration is the term used to describe the optimal alignment of joints. Proper joint centration diminishes friction caused by the motion of the joint, reducing overall wear and tear, as well as allowing forces to be transferred in the most efficient way. Think of joint centration a bit like a wheel on a car – if the centre of rotation is aligned with the centre of the plate then it will deliver the most efficient performance. If this central position becomes misaligned then the wheel won’t spin correctly and may cause subsequent mechanical problems. The muscles around the hip should serve to keep the head of the femur in a centrated position within the hip capsule allowing for free and effortless rotation, a concept called force closure. If muscles don’t function properly, such as when the IR muscles become short and tight, then this can lead to reduced force closure and suboptimal centration.

Centration and Proprioception

If you haven’t already then check out some of Charlie Weingroff’s articles explaining the ‘core pendulum theory’, he talks through this concept far more succinct and detailed manner than I can.

Full mobility is needed for the joint to effectively recognise its neutral, or default, location. When we have a restriction in place however, this ability becomes impaired. A HIRD effectively works to shift what the joint recognises as its neutral position into external rotation, often exacerbating the initial losses of IR.

Full mobility also allows for optimal feedback to the nervous system, this is necessary for sending appropriate signals to the surrounding muscles; the body needs to be able recognise a range of motion to in order stabilise effectively within it. Losses in range of motion due to a HIRD impair the body’s ability to control itself in conditions when it is put into IR, such as during knee valgus (where the knee collapses inwards). Problems of this manner become magnified under fast, chaotic conditions, such as during running and cutting movements in team sports.


As we’ve touched on, movements requiring deep hip flexion (i.e. squats) or rotation require a significant amount of IR to be performed correctly. The most common compensations we’ll see during these movements are excessive pronation at the feet (feet rolling inwards) and knee valgus. These two compensations effectively ‘cheat’ the range of motion by reducing the amount of IR necessary to complete the movement. When performing rotational movements, such as the golf swing, over-rotation of the lumbar spine is also a likely compensation.

Asymmetries between the left and right hip are common in a large percentage of the population, this can also lead to rotation of the lumbar spine during non-rotational movements such as squats.

Faulty Movement Patterns = Injury

I’m sure it comes as no surprise to you that these sorts of compensations often lead to injury. The risk of HIRD related injuries is greatest in rotational athletes due to the speed and sheer volume of faulty movement patterns their bodies are subjected to. The lower back is the most prolific site of injury but loss of IR has also been implicated knee, ankle and groin injuries.


Next time we’ll look at how to assess IR properly and give you some advice on how to go about restoring any losses in range of motion.

Exercises, Performance, Prehab & Rehab , , , , , ,

Facebook comments:


  1. Ted

    I love your articles, Sean! You are very knowledgable.

    May I offer a couple suggestions for topics I would like to see covered in future articles?

    Thank you.

    • Maloney Performance

      Hi Ted,

      Yes, I always welcome any suggestions for articles. I think the best articles often come this way.
      Thanks for your feedback and I hope you’ll continue to pop by in the future!


  2. Ted

    Thanks for the reply, Sean. I will be visiting your site regulalry.

    As for topics, here are some suggestions. Should they have been covered before, I apologize, I haven’t read all of your blog posts yet. If you discussed one of the topics already, could you please be so kind and post the link to the article? Thank you.


    – Does the back squat trigger total body growth and total body strength development?
    Do other squat variations show the same effect or only to a much lesser degree?


    – When training professional fighters (mma, boxing, etc.), which periodization model works best?

    Also: Can the body adapt to highly different stimuli at the same time?
    Linear peridozation tells us to have a max strength period, a hypertrohy period, a power period, an endurance period, … can all of these strength qualities be trained in one session or would then the body not know what to adapt to (as endurance training kind of off-sets max strength development)?


    – We know that pushing muscles (pecs, front delts, supraspinatus, subspapularis, quadriceps) that are much stronger than pulling muscles (rhomboids, rear delts, teres minor, infrapinatus, hamstrings) may cause severe problems and injuries such as kyphosis, shoulder impingement, hamstring tears, etc.
    But can, on the other hand, the pulling muscles ever be too stong?


    Do you think the deadlift can be enough for the lower body or would this lead to severe muscle imbalances (I am thinking of weak vastus medialis oblique for example)?
    Pavel Tsatsouline once suggested this (a deadlift and bent press only program), and Gray Cook once said “maintain the squat and train the deadlift”.


    I hope this makes sense. If it doesn’t, feel free to email me. I am from Germany and know English as a second language only, so please bear with me. 🙂

    All the best,

    • Maloney Performance

      Some great talking points there Ted, I think most of these could provide enough information for an individual article. I’ve had a few requests for my philosophies on periodisation so I’ll definately cover that soon. I really like the idea of a critique of deadlift only programs, I’ve not seen that done before.

      Thank you for the suggestions!

      All the best,

      P.S. Your English is significantly better than many of my athletes’!

  3. Ted

    Thank you, Sean.

  4. Victor

    Hello great article, why does this HIRD happen in the first place?

    • Maloney Performance

      Thanks Victor.
      Generally it’s because people don’t use internal rotation. People will do most things (sit, run, squat, etc.) with the feet pointed out thereby externally rotating the hip. This can often be a consequence of flexibility issues elsewhere though (such as lack of ankle ROM). As the old saying goes ‘use it or lose it’. Of course, traumatic injuries can also affect ROM too.

  5. Des golden

    Can HIRD be congenital? I suffer from chronic lumbar back pain – Physio reckons these are cards I’ve been dealt and it is not reversible. IT band bears the brunt of this when I swing the club.

    • Maloney Performance

      Hi Des,

      From an anatomic point of view everyone will have a genetic ‘end-point’ range of motion. The physio should be able to determine whether you’ve truly reached your limit or if soft tissue structures are still restricting. If so it’s a case of working around it as best you can and making sure you’re applying the general training principles for improving back pain.

      Best wishes,

  6. Pete

    I’m a relative novice when it comes to functional mechanics and the kinetic chain… all researched due to self injuries over time incurred through my work and training. The issue I’m dealing with now is anterior patella pain and patella mal-tracking, which only seems to affect me when I’m in the lower end of a squat (oddly my VMO on that leg seems to have disappeared). But as I’ve sought to mobilize everything: ankles, calves, quads, hips (with a focus on improving external rotation), I’ve noticed I have a huge deficit with IR, which is how I stumbled onto your site.

    The question I have is probably fairly basic, but how is it the squat requires significant IR in order to be done properly as you say? Maybe I’m not visualizing it properly, but I always thought the squat required significant external rotation (i.e. cue of “knees out”). Wouldn’t internal rotation bring about a valgus knee?


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