Weight-bearing is any activity that one performs on one or both feet. It requires that one carry bodyweight on at least one lower extremity. Weight-bearing is an activity that the skeletal system does against gravity. By weight-bearing, the skeletal system adapts to the impact of muscles and body weight and becomes more stable and stronger.
Weight-bearing may be full or partial. In medicine, weight-bearing is of importance in patients who are on the orthopedic floor. Following surgery to fix fractures or repair torn ligaments or tendons, the amount of weight-bearing prescribed depends on the type of surgery. In some cases, the surgeon will prescribe some weight-bearing exercise until the incision heals. In other instances, weight-bearing may be partial and then progressed to full over weeks. Almost any exercise is an option for weight-bearing. In hospitalized patients who undergo repair of fractures, weight-bearing is initially limited due to ambulation. As the muscle strength returns and the range of motion improves, full weight-bearing may take place by controlled exercises performed with the help of a physical therapist.
Weight-bearing can be modified to increase or decrease the load depending on the person’s circumstances. The weight-bearing load can increase through the use of weights; this is extremely beneficial for people with osteoporosis, athletes who submit their bones to tremendous stresses, or women that are postmenopausal and have lower estrogen levels leading to poor bone development. An effective way to stimulate osteogenesis in osteoporotic patients is through physical exercise. Regular weight-bearing, along with vitamin supplementation, is the cornerstone for fracture prevention in these patients. On the other hand, two exercises that involve limiting weight-bearing include cycling and swimming. These exercises help increase the range of motion and improve muscle mass, but they are not very effective in weight-bearing exercises. Athletes who are swimmers or cyclers tend to have lower bone mineral density than other athletes. If the individual has a fracture or is unable to perform other weight-bearing activities, then swimming or cycling are other alternatives.
Weight-bearing exercises help improve endurance, balance, coordination, and improve overall health. Weight-bearing to build up bone mass should be done for at least 30 to 45 minutes at least four times a week. After orthopedic surgery, the surgeon will define the amount of weight that the patient can bear on the leg. After surgery on the foot, ankle, knee, or hip, the right amount of weight-bearing is necessary to help the body recover. Most patients who can partially bear weight need crutches or some ambulatory device.
Weight Bearing Grades
- Non-weight bearing means the leg should not touch the floor or support any bodyweight. The patient uses one leg, and crutches are essential.
- With touch down weight-bearing, the toes of the foot can touch the floor to maintain balance only. At no time should the individual place weight on the leg.
- With partial weight-bearing, a small amount of weight is permissible on the affected extremity. The weight gradually increases so that the patient can ambulate but still needs the use of an ambulatory device like a cane or crutches.
- With weight-bearing as tolerated, the individual may support 50% to 100% of body weight on the extremity. The amount of weight depends on the circumstances.
- With full weight-bearing, the affected leg can carry the entire weight of the body and can ambulate.