When assessing and fixing the cause of knee pain, there is one factor that many completely miss. The motion of tibial rotation. Let me explain.

You see, as you descend into a squat your knee moves towards and (in some people) eventually over the toes. This motion comes from the ankle joint (called dorsiflexion). Restrictions in ankle mobility halt forward knee travel and limit squat depth. Doing so in many cases causes the knee joint to take on more load more quickly, increasing risk of injury.

While improving ankle dorsiflexion is a helpful solution for increasing squat depth and resolving knee pain for some individuals, it’s not the only factor to consider!

The joints of the body do not only open and close in a 2-dimensional plane of motion like we observe when we assess the squat from a side view (called the “sagittal plane” of motion). In fact, there is rotation of the legs (through the “transverse plane”) and also motion occurring side-to-side (through the “frontal plane”).

For example, during the squat motion the knees begin in a straight “extended” position in standing and begin to move forward or “flex” as you descend. At the same time, they also rotate opposite each other in a twisting manner (the femur is externally rotating while the tibia is internally rotating in a process called the “screw-home mechanism).

Sufficient tibial rotation and lateral glide at the ankle allows the knee to assume a more stable and stacked position (in relation to the hips and feet) when performing a squat or lunge movement. These two small yet important joint motions (called “accessory movements”) allow for the knees to track over the toes in the most optimal manner under load.

Squat Descent Sequence Motions:

• Knees:
  • Sagittal Plane: move forward over toes
  • Frontal Plane: open to side
  • Transverse plane: twist-like motion of opposite tibia/femur motions

• Ankles:
  • Sagittal Plane: tibia moves forward over foot
  • Frontal Plane: tibia tilts to the side
  • Transverse plane: tibia internally rotates

These movements described above are “linked,” meaning that a restriction or problem motion in one joint can have a consequence in a completely different joint. For example, limited ankle dorsiflexion can lead to a change in mechanics at the knee joint (contributing to movement compensations in the frontal and transverse planes of the knee and hip leading to “knee valgus” collapse).¹

Also, if a joint has a movement problem in one plane of motion, it can hinder optimal movement in other planes of motion at that same joint. For example, someone who lacks dorsiflexion ankle mobility may also often have limited tibial rotation and lateral glide.² In this case, it’s not always possible to tell which problem started first (a classic “chicken or the egg conundrum”) so both need to be assessed and addressed to ensure we don’t’ leave any stones unturned.

Screening

Tibial Internal Rotation Assessment

Start in a seated position with your feet straight forward. Grab your thigh and don’t let it move at all as you rotate your toes in towards the mid-line of your body. Don’t allow your big toe to rise from the floor! Allowing your foot to roll on its side (excessive supination) as you slide your toes in can give you a false impression of how much rotation is taking place at the tibia. Hold this end position and then perform the same movement with your other foot.

What did you find?

Research and current expert opinions believe that most people should be able to show anywhere from 12-20 degrees of motion with this test.^3-5 However, what we are most concerned with is big side to side differences. If you found a significant limitation on one side, your next step will be to try the banded rotation drill described below.

Lateral Tibial Glide Assessment

Another often overlooked joint motion that is directly tied to rotation of the shin (and therefore the positioning of the leg during lifts like the squat or deadlift) is lateral tibial glide. As you descend into a deep squat, the tibia bone not only internally rotates but also glides laterally over the talus bone of the foot so that the knee can move directly over your toes and stay in proper alignment with the rest of the leg. Here’s a simple way to assess this motion.

Step onto a box that is around knee height or drop into a lunge position. Your toes should be pointed straight forward and your shin at least slightly forward of vertical. Grab your front foot with both hands and push the inside arch toward the ground slightly (the act of pronation). Don’t let your foot move as you then open your hip and drive your knee out to the side as far as you can by squeezing your glutes. Perform this drill on each side and compare the angle your shin assumes in the lunge position. If there is a significant limitation on one side, your next step will be the tibial glide self-mobilization.

Corrective Exercise

Banded Tibial Rotation Drill

Assume a lunge position with your back leg resting on the ground. Place a band underneath the base of your big toe on your forward leg. Grip the ground and establish a stable foot to trap the band against the floor. Next, tension the band by pulling it away from your body as you simultaneously open your knee to the side by squeezing your glute. Try to open your hip as far as possible without your foot rolling on its side and allowing the band to snap out from underneath. Hold this position for five seconds before relaxing back to the start position and removing the band tension.

Start with 10 reps for a 5 second hold. If you’re performing this exercise correctly you will feel your glutes working hard. Then make sure to immediately retest your tibial rotation screen to see if you were able to see any changes in mobility.

It’s important to ensure sufficient glute activation during this drill because one hypothesis for decreased tibial rotation is the glute medius is actually weak or inhibited. If this muscle is not engaging optimally it can lead to an over reliance on the nearby TFL muscle and cause increased tension in the IT band (which can limit tibial internal rotation).

Tibial Glide Self-Mobilization

Assume the same lunge position as the prior test (foot elevated onto a box around knee height or in a kneeling position on the ground). Perform the same motion as per the test by holding your foot down and driving your knee out to the side. You can even give yourself a little assistance with your arm but don’t let your foot roll on its side.

Hold this end position for 5 seconds and perform 10 repetitions. Over time work into setting up with more ankle dorsiflexion (shin angled further forward by driving the knee forward first). You can also position your foot angled slightly inwards (more tibial internal rotation). Then complete the lateral tibial glide movement.

Banded Joint Mobilization

Some, but not all, who present with a restriction in tibial rotation and/or lateral tibial glide also have limitations in knee over toe movement at the ankle (dorsiflexion). If you find with testing that you have a significant difference in your problem ankle compared to the other side, be sure to combine the prior drills with a banded joint mobilization.

Banded Squats

Once you have completed the prior steps to address the movement restrictions at the ankle, we must then take a step back and address full body movement. The squat with a band around the lower shins is an excellent way to do this. While a resistance band loop around the knees is not wrong, placing a band around the lower shins draws attention to the action of the foot and tibia during the squatting motion.

Start by assuming your normal squat stance. If you have chosen the correct size/resistance band loop you will not have any difficulty getting into this position (whereas using a banded loop that is too tight/strong will limit proper stance width). Next, root your foot to the ground by pushing your big toe down as you open your lower body to tension the band. This simultaneous action creates the desired external rotation torque at the hips that must be maintained during the rest of the squat.

Then, perform a few reps by lowering under control for 10 seconds with a 10 second pause in the bottom position. Focus on maintaining the stable tripod foot structure the entire movement and constant outward tension against the band.

When you return to loaded squats, use this banded set up during your first few warm-up sets. One recommended variation is to perform your first rep of any warm-up set with a 5 second descent and 5 second pause at the bottom. Follow this slow rep with as many regular tempo reps as required by your program. This method will help you prime the desired movement pattern and help you feel more comfortable in the bottom position of your squat (where the mobility demand is the highest).

Conclusion

I hope this blog allows you to have a better understanding of an often under looked aspect of the ankle. Restoring proper tibial glide and tibial rotation can create a positive effect in your lifts while also reducing injury risk.

Until next time,

References

References

1. Bell-Jenje T, Olivier B, Wood W, Rogers S, Green A, McKinon W. The association between loss of ankle dorsiflexion range of movement, and hip adduction and internal rotation during a step down test. Man Ther. 2016 Feb;21:256-61.
2. McClay IS, & Manal K. Coupling Parameters in Runners With Normal and Excessive Pronation. Journal of Applied Biomechanics, 1997;13, 109-124.
3. Stanek J, Parish J, Rainville R, Williams J. Test-retest and intra-rater reliability of assessing tibial rotation range of motion by two devices. Int J Athl Ther Train. 2000;25:263-269
4. Stanek JM, Brown B, Barrack J, Parish J. A novel manual therapy technique is effective for short-term increases in tibial internal rotation range of motion. J Exerc Rehabil. 2021 Jun 30;17(3):184-191.
5. Cook, G. (2010). Movement: Functional movement systems : Screening, assessment, corrective strategies. On Target Publications.