Literally, 3 steps will get you into the pool with ProActive Physical Therapy at Noonan Family Swim School. Buoyancy is what makes you feel the “weight loss”. Buoyancy is the upward thrust of the water acting in the opposite direction of the force of gravity. The buoyant force an object feels depends on the weight of the volume of fluid the object displaces. An object in water will experience a greater buoyant force compared to air, because water has more weight. Your center of gravity is generally located in the pelvic region, but your
center of buoyancy is in the mid chest region. When both of theses centers are not aligned vertically, a rotational force results helping maintain upright, head out posture.
Patients do not need to know how to swim to participate in aquatic therapies because they constantly maintain this upright posture. The deeper you immerse yourself in water, the less you weigh and less shock is transmitted through your bones, joints, and ligaments compared to land therapy. With less demands/forces on the joints, more energy efficient movement can occur allowing improved joint mobility and dynamic flexibility. The buoyancy factor is why aquatic therapy benefits patients needing limited weight-bearing (due to surgery protocols, fractures, or a patient being overweight). Here is a quick helpful guide on how much “weight” you can lose:
- water at waist level = 50% of weight through joints lost
- water at chest level = 75% of weight through joints lost
- in deep water = no weight through joints
With the decreased forces on your body, patients are able to walk, squat, climb steps, strengthening their legs and core, and even jog, with little to no symptoms. There is only one problem with buoyancy. . . when you take those same 3 steps out of the pool, your “weight” comes back.