A thread on knee injuries in females and strategies to help minimize their potential

Weakness of the hip abductor & external rotator (ER) muscles is surprisingly common in otherwise normal & healthy females (Malinzak et al, 2001; Robinson, 2007).

That is just one piece of the..
overall puzzle.

Females tend to have a higher Q-Angle due to wider hips. The research is murky whether or not higher Q-Angle leads to more injuries, but honestly I’m not concerned about that as much as the biomechanical relevance of a higher angle.
When hips are wider, the sacrum is in a relatively higher amount of counter-nutation and the pelvic bones follow it into:

- External rotation
- Abduction
- Flexion
You can see how this could cause the deep hip external rotator (ER) muscles to become “shorter” or more “tight”, like the piriformis, glutes, and obturators.
Maclntyre et al, 2008 compared patellar mechanics between knees with no pain and with pain. They found the painful group had a statistically greater lateral shift of the patella, which happens often when Q-Angle is higher.
So if many females have a bias towards ER, why do they have weak ER muscles?

In my opinion it’s because muscles need to stretch to contract effectively. Just because muscle is “tight” does not at all mean it is strong.

What I often see is females
lacking strength in those muscles because they can’t effectively recruit them due to a lack of internal rotation (IR) capabilities of the pelvis and femurs.

There are a TON of theories why they are more predisposed ACL tears, but one aspect of it is related to a lack of hip IR.
If the pelvis and femurs can’t find IR, the femur has a tendency to collapse inwards in an attempt to “find” that IR. Since the lower leg is biased towards ER, the tibia typically likes to stay in ER.

Femoral IR + Tibial ER = Knee valgus.
If there is concurrent femoral IR + Tibial IR + good pronation at the foot, this is normal and knees slightly coming inwards isn’t necessarily bad.

So a key to helping females stabilize knees would be to improve their IR. I have a thread on that here:
This is just one possible explanation.

Other things that help reduce knee injury potential are:
- Increasing relative max strength
- Emphasizing training in three planes of motion
- Plyometrics programmed appropriately
- Adequate nutrition and sleep

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More from @Conor_Harris_

16 Oct
A thread on how to improve hip internal rotation

If you want to:
- Be agile
- Be fast
- Get through the sticking point of a squat
- Deadlift

You want to have adequate hip internal rotation (IR).

However, in my experience it is often missing to some degree in many people.
The hip musculature responsible for hip IR are primarily:

- Adductors
- Inner Hamstrings
- Anterior fibers of the Gluteus Medius
- Tensor Fasciae Latae
In human movement, IR is necessary for mid-stance when we have our bodyweight on one leg and we need to propel it to the next leg. In cutting, we obviously need hip internal rotation to drive out of it effectively in a propulsive manner.
Read 13 tweets
9 Oct
A thread on the biomechanics of a lateral lunge - and why it’s an amazing position for those with tight glutes & piriformis.

This position is know for training the frontal plane, but it’s so much more than that.

Depending on how you do it, you can improve movement mechanics..
through an understanding of the constraints you can use with the exercise.

The lateral “lunge” is honestly a hinge, and that distinction matters when appreciating the context of when we should choose it in a program.

When we hinge, the pelvic inlet (top) comes closer together
while the pelvic outlet (bottom) spreads apart.

Notice where the posterior hip musculature (glutes & that all-so- known piriformis) attach.

When we hinge, we are essentially “spreading apart” that musculature while the pelvis goes into:

-Internal Rotation
-Adduction
-Extension
Read 8 tweets
23 Sep
A thread on how to train the Glute Max

You often hear terms like “gluteal amnesia” or “my glutes are asleep”

Nah, your positioning and exercise selection probably sucks.

Let’s dig in on how to attack the glutes.

We first should appreciate it’s mechanics to best...
train it.

It has a significant role in:
- External Rotation at the hip and femur (leg bone)
- Hip & Trunk extension
- Hip abduction
- Posterior pelvic tilt

And yet, it is hardly active at all during standing and walking (Neumann, 2010). Interesting, huh?
In order for a muscle to be properly contracted, it needs to be stretched. That is what cues contraction of muscles in the human body.

That’s partially why it doesn’t function much in walking and standing, while it does much more in running.
Read 13 tweets
16 Sep
A thread on how to train the Serratus Anterior

Many people are generally aware that the Serratus Anterior (SA) is an important player in shoulder health, but are unsure how to train it.

It has two main functions: Shoulder protraction & assisting in elevation of the arm... Image
The SA is actually a massively important player in overhead mobility.

It needs to hold and “pull” the scapula (shoulder blade) on the ribcage, or else the scapula would be very unstable & overhead mobility is limited. Image
When it can’t do it’s job (usually other factors at play here too), the scapula will be “lost” on the ribcage and won’t have adequate congruency on it.

We see this all the time with “winged out” scapulas. Image
Read 9 tweets
13 Sep
A thread on the biomechanics of the Front Rack position and how to improve your mobility for it

The Front Rack position can be really challenging for some people because it requires maintaining around 90 degrees of shoulder flexion under load (Levangie, 2010).

To improve the.. Image
mechanics of this position, let’s understand what’s happening:

Beyond around 60 degrees of shoulder flexion, the scapular external rotator muscles need to work harder to get the arm overhead due to the progressive upward rotation of the scapula (Neumann, 2016). Image
This means that the Serratus Anterior, Upper and Lower Traps all need to work together to accomplish this.

The Rhomboids, Lats and Pecs need to let go and relax.

This is often the part that is challenging for people. Image
Read 10 tweets
3 Sep
A thread on how mechanics in the foot drives action at the hips

The body is made to interact & react with the ground.

Extension at the knee and hip is cued in the lower body when the foot arch falls/pronates & the supinator muscles are stretched (Neumann, 2010). Image
As Gary Ward says, joints act & muscles react. A stretch on a muscle will trigger it to contract.

The stretch places elastic recoil on the supinator muscles which then spring the foot back into supination upon toe-off in running and gait.

This also allows for a nice reaction Image
up the chain that causes extension at the knee and hip.

However, if the foot is excessively pronated, the supinator muscles are constantly placed on a “stretched” position. This limits them from being able to sense the stretch needed to then spring the foot into supination. Image
Read 8 tweets

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