The elephant in the room is that this study was performed using isometric maximal effort squats rather than a dynamic range of motion. If these findings are only relevant in static positions, the concepts could be useful in the post-surgical setting.
If what is true for these isometric findings holds true for dynamic motion, it would direct box height selection in Box Squats as well as point out the need for some athletes to cultivate additional recruitment at end range. Perhaps the use of Pause Squats or 1 and 1/4 squats at full depth for athletes (olympic lifters) who find themselves at angles approaching 140 degrees flexion.
Also, this could validate the use of partial depth squats and walkouts at above 1RM weight. . . interesting. . .
Here’s the link to the full text article-
If your knee is hurting after last week’s 16.4 workout, don’t be so quick to blame the wall balls. Your kipping handstand pushups may be to blame.
When an athlete does a good job of recruiting the hips in the hspu kip, a violent end range knee extension at lockout is the result. This differs from the crisp knee extension in other movements such as the kettlebell swing because the lower extremity meets no resistance making it an open chain movement with with zero resistance to guide the normal screw-home mechanism of the tibia. The result can be repetitive hyperextension of the knee through the course of say 55 handstand pushups. Add the fact that leaning into the wall to achieve a legal rep further levers the knee into extension, and it should be no surprise that many athletes are limping their way into week 5 of this year’s Open.
Biomechanics of knee extension in hspu-
The likely source of knee pain following a set of kipping handstand pushups is the anterior cruciate ligament. The ACL comes to tension when limiting anterior translation of the tibia at end range flexion. In hyperextension, the ACL is vulnerable to impingement by the intercondylar notch roof of the femur. See article HERE.
The Take Home- Explosive knee extension in a kipping hspu is different than in other movements. The legs are flailing into the sky without any resistance to prevent hyperextension. The result is like the ACL getting slammed in a door.
The result of this repetitive ACL impingement is inflammation within the joint space and pain at end range flexion. The inflamed joint feels unstable, clicks and pops but should not lock up or give way. Getting into the bottom of a squat is very difficult in the week that follows this injury as the joint is swollen on the posterior side and the aggravated ACL is at tension at end range flexion of the knee.
Knee sleeves and Rock Tape
- Neoprene knee sleeves
- Hamstring Rock Tape
- Adds some tactile awareness of knee end-range
- Coactivation Exercises- Russian Swing/ Power Swing
- Focus on coactivation of glutes with quads to avoid end range extension.
- Hamstring prep- Death March/ Kang Squat
- Coactivate glutes, hamstrings, and quads during knee extension.
- Stay on the wall. Striking the heel into the wall at the top of the motion increases hyperextension forces. If possible, glide the heels up the wall as the knee approaches lock out.
- Closer hand placement-
- The further the hands are from the wall, the greater the knee is leveraged into hyperextension at lockout.
It is unlikely that serious mechanical damage has taken place. If you have apprehension or are experiencing locking up or giving way of the joint, have it assessed by your local knee specialist. Otherwise you are dealing with painful inflammation of the ACL.
Inflammatory measures- 4-7 days
Heat / Ice contrast therapy. 6/1 ratio
- 20 minute sessions level 8
- 3x/day on empty stomach
- The poor man’s normatec
Pray that there are not pistol squats in 16.5.