Definition/Introduction

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.[1] Regular weight-bearing, along with vitamin supplementation, is the cornerstone for fracture prevention in these patients.[2] 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.[3] 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.

Issues of Concern

Some significant issues when it comes to weight-bearing are obesity, limited mobility due to disease, or bearing weight too early following a fracture or orthopedic surgery. When circumstances limit the ability to ambulate and bear weight, the risk of obtaining osteoarthritis or osteoporosis increases. Mechanical loading with weight-bearing activities have been shown to inhibit bone loss and may reduce arthritis-mediated bone loss.[4] For certain fractures, particularly periarticular fractures, surgeons recommend a period of modified weight bearing to allow proper healing.[5] For procedures like an epiphysiolysis, weight-bearing is discouraged by most teams, at least in the early stage. Weight-bearing is permitted once the epiphysiolysis is stable, and there is a complete fusion of the sub-capital growth cartilage.[6] Other fractures stabilized with hardware have reported low complications with early weight-bearing.[5] Rehabilitation following total knee arthroplasty, specifically weight-bearing biofeedback and balance control, have shown to be beneficial to the recovery process of the patient.[7] This shows there are certain circumstances that indicate early weight-bearing and other times when modified weight-bearing indicated. To ensure a speedy recovery, a clear discussion with the surgeon and patient regarding expectations with recovery.

Clinical Significance

Weight-bearing is essential for bone healing in patients with autoimmune disease, fractures, and following orthopedic surgery. Low-intensity weight-bearing exercise has shown to be beneficial in bone healing over non-weight bearing exercises.[8] Additionally, weight-bearing has been demonstrated to help the healing response, particularly following Achilles tendon rupture, through increased metabolism and functional weight-bearing mobilization-induced upregulation of glutamate.[9] Despite these advantages, weight-bearing may not be an option for people that are affected by rheumatoid arthritis. Once this disease has affected a weight-bearing joint, the individual must remain on pharmacotherapy or is at risk for a significant reduction in activities of daily living due to joint damage.[10] Based on the circumstances of the individual, weight-bearing has advantages and disadvantages.

Nursing, Allied Health, and Interprofessional Team Interventions

Clinicians expect patients who return to the hospital floor following orthopedic surgery to bear weight to expedite their recovery process and reduce post-op complications such as DVTs or decubitus ulcers.[11] Surgeons must convey their post-op expectations for mobility, weight-bearing, and range of motion to the patient before going to the operating room. After surgery, nurses have the responsibility to remind and encourage the patient to participate in early ambulation. Nurses are challenged by patients who are not confident enough to mobilize following a lower extremity joint surgery or fracture stabilization. This situation leads to decreased weight-bearing, which can hinder the recovery process and future mobility of the patient. If the patient does not comply, the nurse can communicate that to the physician who could provide re-education to the patient on the need to mobilize to improve recovery. The nurse could also communicate ambulation issues to the physical therapy team, who could then work with the patient to increase knowledge and confidence. Physicians should seek the counsel of a pharmacist to provide proper analgesia without sedating the patient; this could help motivate the patient to mobilize and bear weight while minimizing discomfort. Education and encouragement from the patient’s entire care team increase the likelihood of ambulation, therefore enhancing patient safety and improving patient health.