When you watch powerlifters squat and deadlift you can see a unique difference in the styles of a squat.  The upright position of the Olympic lifter stands out in my mind.  Where the powerlifter conforms to a more forward leaning position.   A mechanically similar movement with the same name, but a subtle and unique variance of the similar pattern.  High bar vs low bar squatting may create an argument,however you can see high bar squatters who demonstrate low bar squatting technique when fatigued.   Failing in a squat or squatting in fatigue generally follows a similar pattern more similar to a powerlifters technique.

I’m reaching here, but if you have seen the mars rover and how they packed it tight into the shuttle so it would take up as little room as possible and still be able to unfold itself upon arrival, you can see a similar concept from a baby in fetal position.  The body structural mechanic tendency is to collapse toward this internally rotated position.  This parallels with fatigues ability to internally rotate a body into it’s structurally weakest position.  When you squat fatigue tends to internally rotate your hip when you bench fatigue flares your elbow so you can internally rotate your shoulder.  These examples aren’t unique they are the body’s natural tendency.

The powerlifter has mechanically strengthened a more internally rotated position by racking the bar low and allowing the position to internally rotate his shoulder and flex his hip into lordosis.  Where you will find the Olympic lifter removes the lordosis at the top of his squat an moves to hip extension you will also find a tendency for the Olympic lifter to have elbows further under the bar and less internally rotated shoulders.  Neither of the styles are incorrect because both are conforming to the sport.  However longevity would favor the Olympic lifters posture, but structurally the body will always internally rotate when at maximal weight or in a fatigued state.

Within an adaptation cycle to a lift there is also a latent tendency to assume a more efficient internally rotated posture.  In a front squat sometimes the body finds a way to inhibit muscles in order to fire active muscles more efficiently.  I believe this is where people with mechanically correct front squat tend toward wrist pain, because they relax the hand on the bar. Relaxing the wrist flexors on the bar so the body relies on tendon and ligament of the wrist rather than muscle to maintain joint integrity.

Integrity of a movement pattern can also be hampered by muscle belly length distortion. You will find that the the bodies feedback computer system pays attention to length tension and various and other stimulus.  The duration of a length tension can hinder efficiency of a contraction.  The problem is sometimes in order to understand information individuals make up things like muscle activation work which is a good concept, but some authors have criticized the verbiage because the idea assumes that the muscle is inactive and you are activating it.  The problem is at certain lengths the muscles activity is irrelevant because it doesn’t efficiently provide tension when needed in a movement pattern.  The glutes in opposition to the abductor and hipflexors are a large part of the issue from this stand point.  So sitting for a long duration will lengthened glutes is a compromised position making glutes become slack. This slack creates a greater reliance on other muscles to maintain optimal position in a movement pattern. So rather than not being “activated” they are rather inefficient at the length when they are engaging along with hipflexor and adductor being short and tight.

Long story short I think this is the reason that lifting legs 2 to 3 days in a row or any lift for that matter will allow for more efficient presses and or squats so long as volume is divvied up into frequency that is not much greater than a single day.