Unable to produce speed months after injury

Any time there is an injury the body moves differently. There is also excess tension as CF stated. An example: My tendon tear caused my chronic stiff shoulder to become much worse, which itself caused my walking (once I was able to walk again) to be worse. You may have not only tightness but some altered mechanics that you aren’t aware of. I suggest some good massage to reset muscle tonus, posture, etc.