Having a lack of hip internal rotation will cause back pain, because your spine and your pelvis will compensate for the restricted hip movement, which results in muscle imbalances and increased stress on your spinal structures as well as altered mechanics, which often also result in lower back pain, stiffness and even sciatic nerve irritation.
When your hips cannot rotate properly, your lower back and your pelvis are then forced to move more in order to achieve the necessary motions such as walking or squatting and create strain.
And tight hip muscles like your external rotators or hip flexors and weak internal rotators create instability, which cause overactive muscles in your lower back, like your multifidus or piriformis, which can become painful or compress the nerves, which include your sciatic nerve.
And small and repeated compensatory spinal movements also add up and can cause microscopic injuries to your spinal structures over time.
A lack of hip internal rotation can also cause knee pain, as a lack of hip internal rotation is also a common cause of knee pain that is often overlooked.
When your hip joint can't rotate inward like it should, your knee will compensate by twisting during daily activities, which can lead to injuries such as knee cap pain or patellofemoral syndrome, meniscus damage and even ligament strains.
The hip is naturally designed for rotation, while your knee is a hinge joint also known as "flexion/extension".
When your hip internal rotation is restricted, your knee has to rotate and causes abnormal stress.
Reduced hip internal rotation often also causes your knee to collapse inward, "valgus" during squatting, walking, or jumping, which places pressure on the inside of your knee.
Restricted rotation of the hip is also associated with an increased risk of an ACL injury.
Internal hip rotation is inhibited mainly by structure and soft tissue factors such as a tight posterior hip capsule or the ischiofemoral ligament and even overactive or tight external rotator muscles, like the obturator internus or piriformis muscles.
Other things that can inhibit internal hip rotation are bony abnormalities like femoral retroversion or even femoroacetabular impingement or even poor pelvic control, poor foot control or even poor core control.
As for the posterior capsule tightness being a cause of inhibition of the hip rotation, the rear part of your hip joint capsule can become stiff and prevent your femur from rotating properly like it normally should.
The nerve that controls hip internal rotation is the superior gluteal nerve (L4–S1).
The hips internal rotation is controlled mainly by the superior gluteal nerve (L4–S1) nerve, which also innervates the gluteus medius, the gluteus minimus and the tensor fasciae latae.
These muscles are also responsible for rotating your thigh inward.
Other nerves like your femoral nerve, via pectineus may also assist n internal hip rotation.
The superior gluteal nerve (L4–S1) is what innervates your gluteus medius, gluteus minimus and tensor fasciae latae, which are the key internal rotators.
And the gluteus minimus, "anterior fibers", gluteus medius, "anterior fibers, and the tensor fasciae latae are what perform hip internal rotation.
And the assistant nerves like the obturator nerve also helps to stabilize, while your anterior femoral nerve branches provide additional muscular support for internal rotation.
The hip internal rotation, is the inward twisting of the thigh bone, also known as the femur within the hip socket.
Hip internal rotation is also crucial for daily movements like squatting, walking and even pivoting, which allows for smooth gait and prevents lower back pain and knee pain by moving your foot inward relative to your body.
Having limited internal hip rotation, which is often due to tight hip capsules or weak rotators leads to compensation as well as causes pain and dysfunction and improving it involves using targeted stretching and strengthening exercises to regain motion once again.
The reason hip internal rotation matters is because it allows for movement and allows for you to rotate your thigh bone or femur towards your body's midline.
Internal hip rotation has a normal range of around 30 to 46 degrees, which is essential for stability and alignment and it allows you to put on shoes, walk, climb stairs, play sports and sit comfortably.
The consequences of a lack of internal hip rotation are back pain, knee pain, "knees tracking inward" shorter strides and flat feet.
Common signs of limited internal hip rotation include knee pain, lower back pain, feet turning inwards when walking and difficulty in squatting deeply.
To improve your internal hip rotation you can do some exercises like quadrupled band assisted internal rotation, face down feet opens, side planks and stretching.
For stretching, focus on creating space in the back of your hip capsule.
Doing side planks can improve mobility and strength in supporting the muscles.
For face down feet opens, lay on your belly, knees bent, lift your knees and then splay feet out and in and rotate your thighs inwards.
For Quadrupled band assisted internal rotation, lay on your hands/knees with a band around your ankle and then rotate your foot inward against the resistance.
Cause of limited hip internal rotation include sitting too long, tight hip capsule and overactive external hip rotators.
And so improving your hips internal rotation can help the body move more efficiently and reduce strain on your lower back and knees and prevent injury and improve overall function.