Dooley Noted: 10/7/2016
TFL is a gorgeous power generator of the hip and pelvic stabilizer.
Understanding its functional anatomy can be crucial in helping a patient or client with pelvic and hip issues.
TFL originates on the anterior part of the ilium, just below the anterior superior iliac spine (ASIS).
It takes a very long pathway down the femur, just to bypass attaching to it. Via the iliotibial tract, the TFL inserts upon Gerdy’s tubercle, a projection on the anterolateral aspect of the tibia, just lateral to the tibial tuberosity where the quadriceps femoris muscles attach.
When in concentric contraction (the short position), TFL has the ability to move in three different planes.
On the X axis: hip flexion and knee extension
On the y-axis: hip abduction
On the z-axis: hip internal rotation and knee lateral rotation
Since a muscle can only be powerful on one plane at a time, TFL has crucial actions and with certain moment arms in gait and in activities.
TFL wants to be an accessory quadricep so badly, that this muscle embryonically migrated from the gluteal region to the anterior thigh. This makes the TFL a wonderful connection between the quadriceps and gluteus maximus during the propulsion phase of gait.
In propulsion, TFL is helping to externally rotate the knee, as well as abducting the hip. It is being stretched on the X axis at the hip, making it a very powerful force generator when moving from propulsion into the swing phase of gait.
Conversely, the TFL is short in hip flexion and internal rotation during the suspension phase of gait, which looks much like the front leg on a single leg lunge, squat, or deadlift.
This eccentrically loads the muscle at the knee in both planes and the hip in the Y plane for pelvic stability and for preparation to explode into propulsion.
TFL receives innervation from the superior gluteal nerve (L4-S1), the nerve that drives hip internal rotation.
More often than not, a lack of hip internal rotation is usually not a lack of flexibility in this range. That’s why sitting statically in internal hip rotation rarely gets you anywhere, nor does most mobility work in internal rotation.
Lumbar stability is usually the concern, such as an L4-L5 disc herniation, affecting the L5 nerve root.
This impacts the hip’s internal rotators, like TFL, gluteus medius, and gluteus minimus, which receive their major spinal innervation from L5. (Think: L5 on the side of the hip).
These people will then lose their ability to stabilize that side of the pelvis, as well as their ability to properly internally rotate the hip on that side. Thus, they can do mobility work for internal rotation out the wazoo, but they lack the lumbar stability to support the reduction of L5 nerve root impingement.
These same clients typically have pain when in a supine position when raising the legs. A TFL-located pinching may occur, indicating a weakened and painful muscle without proper core support. This commonly happens in hip sagittal plane movements.
Conversely, an overworking TFL can create pain on excessive force generation, such as in the frontal plane on hip adduction or in a person who overly supinates the foot (since TFL encourages supination).
Common compensators for an overridden and unsupported, weakened TFL:
1. Sagittal plane: iliacus, quadriceps femoris, lumbar extensors
2. Frontal plane: hip abductors and adductors
3. Transverse plane: sartorius, deep 6 lateral rotators, popliteus
* Look for weakened or painful transitions from propulsion.
Common structures whose movement is overridden by an overactive TFL:
1. Sagittal plane: psoas, recurs femoris
2. Frontal plane: QL, gluteus medius, hip adductors
3. Transverse plane: deep 6 hip lateral rotators
Consider TFL corrections in both long and short positions, and consider that a painful TFL could be tight and inhibited.
Digging on it may not be the only answer.
As always, it’s your call.
– Dr. Kathy Dooley