T Nation

Quad De-Activation After Injury

I’m curious to see if anyone has experienced an inability to fully engage a muscle after an injury?
I sustained a grade 2 MCL sprain on the right knee during a softball game about 4 weeks ago. I was still able to deadlift and do leg press at normal training volumes without increased pain 2 days after the injury. I couldn’t do and still can’t do back squats, front squats or lunges. But despite doing legs 2-3x/week plus stationary bike my right leg still atrophied 2 inches and it feels like I can’t fully contract my quads. I get maybe 50-60% activation compared to my left. Anyone else experience anything like this?

Were you diagnosed by a professional?

Are you working with a physical therapist/ physiotherapist / some other health professional to rehab your injury?

Dunno how much 2 inches equates to in terms of mass but 4 weeks is really not long enough to lose a lot of muscle or even just weight unless your are starving yourself. Perhaps there has always been a difference in size between your left and right and your injury has only slightly increased the difference?

What problems are you having exactly? Is it pain? Where around your knee? When/where in the ROM e.g. deep / knee bent to the max

I guess it’s not unusual for a muscle to be inhibited after an injury (maybe muscle activation isn’t the right term) due to pain or fear or pain/reinjury. In significant knee related injuries or surgeries e.g. knee replacements one of the first kind of baby steps is to do isometric or small/inner ROM contractions of the quads and even electrical stimulation by itself or in conjunction.


Hi, I’ve had two ACL reconstructions and both times it took a while for my quad of the injured leg to activate 100%. This came back over time and found isometric holds helped this. Similar to the video above just with a rolled up towel under the knee and then tensing my quad for 5-10seconds. repeating multiple times. Along with this i found stretching the antagonistic muscle (hamstring) also helped due to it naturally tightening up trying to protect the knee from further injury.

Terminal knee extensions with light band resistance (to start) could be helpful.