There’s something you must have to stay alive beyond food, air, and water.
Gravity.
All biologic systems of the body – lungs, heart, bones, muscles, joints for example – need some form of applied external force or stress to maintain or improve their health. This stress comes from gravity.
This is especially true for astronauts. One of the main problems with prolonged space flight is the detrimental effects to the body from the loss of gravity.
When astronauts spend a long time in space, they battle loss of bone density, muscle strength, disturbance in balance, and problems with the cardiovascular system among other issues.
I divide gravity into three environments: Sub-Gravity, Gravity, and Super-Gravity.
A Sub-Gravity environment contains a range of forces that are less than the weight of the body. A Gravity environment’s forces will be equal to the weight of the body while a Super-Gravity environment will have loads that are greater than the weight of the body.
Here are a few examples:
The force due to gravity is what makes our bodies work optimally. But, when you hurt or feel stiffness or aching with everyday activity or various types of exercise, if you reduce the effect of gravity, in almost every case, you’ll feel better and actually get stronger.
For example, if your knee hurts while going for a walk (Gravity level force), you might be able to walk in pool without any discomfort (Sub-Gravity force). In the pool, you’re still applying a force to your leg and knee but it’s much less than walking on land.
In a similar way, if your knee hurts performing a single leg squat (Gravity level force), it may not hurt while performing a squat with both legs (Gravity level force with a reduction in total load – one leg versus two).
Problems arise – pain, stiffness, aching for example – when you are functioning or exercising at a level too far beyond what the body can do or needs to do. In a way, it’s like what happens to astronauts when they return to Earth. For a period of time, they have to be careful. Their muscles, bones, and other tissues can’t handle the repeated loads of Earth’s gravity. Their entire body has adapted to Sub-Gravity loads (some astronauts report difficulty speaking because even their tongue – a muscle – has adapted to the micro-gravity loads of space). Astronauts often go through several months of physical rehabilitation to restore their strength and mobility.
Imagine what might happen to an astronaut who has been living on the International Space Station for a year if, after returning to Earth, they immediately started lifting weights. The Super-Gravity load of the weights on their Sub-Gravity adapted bodies would result in injuries and delayed recovery.
The same kind of thing can happen to people with Knee OA.
If your knee feels okay walking around and maybe climbing stairs, you know your “Functional Zone” is within body weight forces or gravity. But, if your knee starts to hurt when you run, you’re now well outside your Functional Zone. Your knee is exposed to Super Gravity forces but it can withstand Gravity level forces.
One of the keys to rebuilding your leg and body strength is understanding how to adjust exercise to help you move from a Sub-Gravity level or tolerance to Super-Gravity.
Weak joints need to be nudged to get stronger; not pushed.
Robert is an energetic, trim, attorney in his 40’s. He goes to Bikram Yoga several times a week for his “fitness” routine (Bikram Yoga is performed in a very warm environment). Fitness is critical to him; it’s part of his lifestyle. He likes the way Bikram Yoga makes him feel and he thinks it helps him keep his weight under control.
When I asked him if he ever did any other kind of exercise he said, “Oh, yeah, I used to work with a trainer at a gym but I just found that I hurt more and more after the sessions. I mean, it kept me lean and everything, but my body hurt too much.” In Robert’s case, he found another way to exercise that was kinder and gentler on his joints but not kind and gentle enough. He said that he still hurt; just not as much or as often.
To work through a joint weakness, you first get rid of everything you know to do for muscles including how hard you work, how fast, and how long.
Joints like things to be easy. Muscles like things to be tough.
Joints change slowly. Muscles change fast.
Joints need a lot of motion. Muscles need a lot less.
The kind of exercise you do to strengthen muscles is way too hard for a weak joint. In fact, weak joints are often the reason people either don’t exercise or eventually quit. They hurt too much; too often.
Joints need to be nudged into health; not pushed.
Joints are not muscles.