where the foam roller won't reach

Clouds mirrored in the surf at low tide. Taken by PKSenagore July 2017. All rights reserved.

SELF-MASSAGE FOR DIFFICULT TO REACH BACK-OF-THE-KNEE AREA 
For runners with tightness at the back of the knee, just in the upper outer/lateral body of the calf muscle but below the joint that doesn’t seem to respond to the usual stretches and foam rolling, perhaps this video will help. The massage demonstrated in it targets the popliteus muscle, which is deep and often difficult to isolate with self-massage techniques.
 
If you drive or sit with a computer on your lap for extended periods, or must walk up stairs quite a bit like I do, you might be experiencing this tightness. I did not seek a proper diagnosis from a physical therapist or physician for this relatively mild but recurrent problem, and can’t say with certainty that popliteus muscle strain is the source of my discomfort.
 
However, this lacrosse ball roll-out was able to provide a great massage in the area that was tender and a bit of relief almost immediately. The leg/knee/calf still must to be rested a few days (no running/intense walking until back to 100% function), so daily strength training will be substituted as well as the massaging.
 
Afterward, I realized that this high outer calf area wasn’t being reached with the usual foam roll and passive stretching moves.  Because tightness flares up after a lengthy drive or laptop session, and with running up and down stairs (not for training but housework) I’m happy to have found a massage method to keep in my ‘toolbox’ to use routinely on both legs after recovery. 
 
Caution: ONLY MUSCLE bodies should be massaged, not the joint space.  If you have significant discomfort and decreased function in a knee, seek medical advice. Making a self-diagnosis of a serious problem and attempting to treat it can worsen the situation and lengthen and complicate your recovery.

Trainers or coaches please comment.
 
RUN HAPPY!
 
Posterior Knee Massage: Pain and Mobility (popliteus) by Activ Chiropractic
https://www.youtube.com/watch?v=0t03rzBn8lo