How many of you would enjoy having less stiffness or pain in your knees? Wouldn’t you love to be able to squat down to pick up your children and not pay for it later with aching knees? How many of you have stairs at home or work and avoid them because of the stiffness and pain in your knees? How many of you limit your daily walking, running, or playing with your children or grandchildren due to knee pain?
Stay tuned everyone, because over the last 18 years as a physical therapist specializing in ergonomics and injury prevention, I’ve observed some of the most common awkward sitting posture habits that I believe are the leading causes of knee stiffness, pain and injury overtime.
The three most common awkward sitting posture habits that are damaging and aging your knees:
- Pulling your legs back underneath your chair when sitting
- Crossing your legs
- Sitting on your feet
When you pull your legs back underneath your chair, your hamstring and calf muscles are in a shortened position and therefore get stiffer and tighter overtime. The more often and prolonged time you pull your legs back underneath your chair, the tighter your hamstring and calf muscles will become. When you pull your legs back underneath your chair, you are typically on your tiptoes which shorten your calf muscles too. This awkward posture has the same impact that walking around on your tip toes would have.
From observing groups of people sitting, I believe that approximately 60% of us normally pull our legs back underneath our chairs when we sit. I notice this awkward and forceful posture increases while eating, with 80% to 90% of people. This posture increases the stiffness, pain and MSD risks for your knees and lower back over time. The more you flex or bend your knees greater than 90 degrees, the faster you may wear out the cartilage in your knees too. This is one of the leading risk factors for knee osteoarthritis and possibly a future total knee replacement.
Crossing your legs and sitting on your feet compress the sciatic nerve that runs down the back of your leg. Overtime this may lead to sciatica nerve pain and burning that runs down the back of your leg, loss of muscle function over time, lower back pain and stiffness, or even an injury.
Working Smart Industrial Athletes sit with their feet flat on the floor or on a footrest when sitting to protect their knees and lower back. Ideally, if you are able, you should alternate between sitting with standing by looking into the purchase of a sit to stand adjustable desk.
When you are sitting or must sit, make sure to get up and move for 30 seconds to three minutes at least every hour if you are able. If you are not able to get up, try to fidget and rise up on your toes or heels, or tap your feet to kick start the blood supply in your lower legs when sitting.
WorkSmart dynamic stretches help protect your knees, reduce pain and stiffness and improve your quality of life. Perform the following dynamic stretches one to two times each day to keep your knees, lower back, and body healthy and flexible, with reduced stiffness and pain.

- Calf Stretch - Stand facing a wall in a staggered stance with your left foot forward and right foot back (toes facing the wall to stretch your right calf). Have both hands reaching forward at shoulder height and lunge forward until you feel a stretch; then, hold for three to five seconds. Shift your hips to the right side and hold three to five seconds; shift hips to left side and hold three to five seconds. Repeat twice on each side. Then, look back over your right shoulder and hold three to five seconds. Next, look back over your left shoulder and hold for three to five seconds. Repeat this twice on each side. To complete the stretch, repeat with the right foot forward and the left foot back to stretch your left calf.
- Standing Hamstring Stretch - Stand up and extend your right leg in front of you onto a chair (without wheels and against the wall for stability) or the stairs, and gently pull the toes of your right foot back towards your head. Reach both of your arms in front of you towards your toes and hold for three to five seconds. You may want to perform this dynamic stretch by a wall, another chair or by the railing of the stairs as this stretch does challenge your balance. Roll your leg/foot to the inside and hold for three to five seconds, then roll your leg to the outside holding for three to five seconds. Repeat this leg rotation for two to three repetitions.
Another way to tweak this dynamic stretch is by reaching with both of your hands the opposite direction of your leg/foot rotation. Note: It is very common for you to feel more stiffness or pain when you rotate across the front of your body because the hip internal rotation is typically very limited due to how much we cross our legs or stand in the toe out position.
- Sitting Piriformis Stretch - This stretch is performed by sitting up tall and crossing your right leg over your left knee to stretch the right side. Turn your body to the right and gently pull your right knee up towards your left shoulder and hold for three to five seconds. Repeat two times. Then, repeat with your other side. You will want to perform this WorkSmart stretch more often to the side that you find to be tighter while performing this stretch. The side that is tighter is the side you tend to cross or sit with your knees apart and stand in a toe out posture for longer periods of time.
- Hip Flexor Stretch - Stand in a staggered stance with your right foot forward and left foot back, with feet slightly wider than shoulder width apart. You may put your front foot on a chair or on the stairs to increase this stretch, but I recommend beginning in this staggered stance posture. Now lunge forward and lean back with hands on your hips and reach with your left hand back overhead holding for three to five seconds. Repeat two to three repetitions. Now, reach with left arm straight up and then side-bend to the right away from your back leg and hold for three to five seconds for two to three reps. Finally, rotate and reach with your left arm across your body like reaching back behind you and hold for three to five seconds, and repeat two to three reps. Now switch stagger stance putting left foot forward and right foot backward and repeat above directions for two to three repetitions to stretch out your hip flexor muscle that gets shorter and tighter the longer you sit.
I’ll be looking forward to seeing you sitting up tall, or standing in a staggered stance with both feet flat on the floor or on and footrest and a huge smile on your face as your knee pain, stiffness and well-being improves!