The role of exercise in fortifying bone health.

Achieving and maintaining bone health is an important consideration throughout one’s life span. PTs are in a unique position to improve bone health by promoting osteoporosis education and encouraging physical activity. Exercise is an important component of the prevention and treatment of osteoporosis. Individuals diagnosed with osteoporosis should seek medical advice from a PT who can design an exercise program that addresses safety issues and is tailored to the individual’s physical condition.

Bone is a dynamic structure that depends on mineral deposition, specifically calcium and phosphorus. The term “bone density” indicates how tightly the bone is packed. Throughout the life span, bone remodeling occurs in two phases: bone resorption, followed by bone formation. During the bone-resorption phase, osteoclasts break down bone, creating small surface cavities. Then,  in the bone-formation phase, osteoblasts fill in these cavities with new bone. Many variables, including hormones, nutritional status, and exercise, impact this process. If bone resorption and bone formation are balanced, bone strength is maintained.

With osteoporosis, this balance is disturbed with a resulting net loss of bone mass and density.¹ The concept of a “bone bank” is helpful during patient education. In childhood through early adulthood, our aim should be to deposit as much bone as possible. By keeping this bone account healthy with adequate calcium and exercise, we are in a much better position for when bone-tissue withdrawals exceed deposits.² It is important to remember that most individuals reach peak bone mass between the ages of 20 and 30.1

Public Health Concern

The Centers for Disease Control and Prevention (CDC) has taken an active role in osteoporosis education by outlining some of the risk factors associated with osteoporosis. These include being female, postmenopausal, or older; having a small body size; eating a diet low in calcium; being white/Caucasian; or being inactive.³ The National Osteoporosis Foundation lists additional risk factors, including: a personal or family history of fractures; smoking; excessive alcohol consumption; taking certain medications, such as corticosteroids; and certain medical conditions, such as hormonal imbalances, bone-marrow disorders, organ transplantation, and cancer. Amenorrhea in women of childbearing age needs medical attention.1 Because osteoporosis often remains a silent disease until a fracture occurs, it is important that the PT identifies potential risk factors and facilitates the process of proper testing and treatment.

Bone-density testing should not be feared, since it is painless, noninvasive, and has low radiation exposure. Low bone mass is diagnosed as osteopenia. Further bone loss leads to osteoporosis.1 Proper diagnosis is essential so that a treatment plan can be established for the patient. Subsequent bone-density testing can be performed to monitor the patient’s status and response to treatment.

Treatment Options

Treatment goals for a patient who has already sustained a fracture would include the promotion of healing and the prevention of further fractures and disabilities. For those with diagnosed low bone mass without a fracture, the treatment goals would be to focus on preventing further bone loss and possible fractures. A team approach is needed, as many medical professionals are involved in osteoporosis prevention and treatment. Medications that have been developed to combat bone loss include bisphosphonates, Calcitonin, estrogen/hormone therapy, parathyroid hormone, and Raloxifene. Many of these drugs have been clinically shown to reduce fractures or fracture risk.⁴ As with all medications, there are potential side effects and interactions, so patients should work closely with their physicians and pharmacists. Medication development for osteoporosis has shown additional benefits. A study in the Archives of Internal Medicine indicated that these new medications had a positive impact on osteoporosis identification and treatment.⁵

Prevention and treatment of osteoporosis includes nutritional care. Calcium and vitamin D are especially important for bone health. Calcium requirements change throughout the life span. In addition, many variables, such as aging, can impact calcium absorption.¹ As many foods can influence calcium absorption and excretion, patients should be referred for a nutritional consultation. They should also speak with their physician and/or pharmacist about the possible use of calcium and vitamin D supplements.

Exercise and physical activity are crucial for improving and maintaining bone mass. Weight-bearing and resistance exercises are especially important to prevent and treat osteoporosis. During weight-bearing exercises, the body must work against gravity with various degrees of impact. Resistance exercises use muscle strength to increase muscle and bone mass.1 Physical activity should be promoted early in life when building peak bone mass.

The CDC sets the following recommendations: “Children: Engage in at least 60 minutes of moderate physical activity on most, preferably all, days of the week. Adults: Engage in at least 30 minutes of moderate physical activity on most, preferably all, days of the week.”3 The National Osteoporosis Foundation recommends the following: “Weight-bearing activity should be done at least four times per week, and resistance training should be done two to three times per week.”1

Many Americans do not meet these recommendations. Before beginning any exercise program, the individual should consult with a physician and a PT. Someone with an established diagnosis of osteoporosis should avoid activities that promote fractures or falls. To prevent injury and promote exercise adherence, all activities should be progressed slowly.

Physical Therapy Intervention

The physical therapy examination would be quite extensive. The medical and social history would include any surgical repair of fractures, such as joint replacement or kyphoplasty. Assessment of cognition, communication ability, and learning style is necessary when establishing a home-exercise program. The systems review, with tests and measures, would include posture assessment, spinal-mobility measurements, strength and endurance, aerobic capacity, balance, functional mobility and gait, functional testing and fall-risk assessment, and pain reports. The patient’s home and community environment would be investigated.

Treatment issues would include acute or chronic fracture management, pain management, body mechanics, the use of adaptive equipment to prevent skeletal compromise, and postural training. Patient education would cover topics such as osteoporosis management, lifestyle management, and fall-prevention issues. Fall prevention may include a home assessment and appropriate modifications. Safety issues and fall-recovery training would also be addressed.

Gait training is an essential component. The individual may need an assistive device to promote safety during gait. Balance training is another critical treatment consideration. Establishing a home exercise program that includes weight-bearing activities and resistance training would be a long-term goal of any therapeutic intervention.

Physical Therapy Exercise Prescription

As PTs, we have an obligation to educate our patients about safe, individualized exercise programs. No exercise should cause additional pain. Exercises may need to be modified. Patients with osteoporosis should avoid any activity that would make them vulnerable to falling. The risk of fracture must never be ignored. When choosing appropriate weight-bearing activities, consider the patient’s current bone status, functional limitations, and comorbidities.

For example, a walking program might be indicated for a patient with low bone mass. Walking is generally tolerated well by most people. Problems associated with walking could include inappropriate clothing and footwear, poor neighborhood safety, and extreme environmental temperatures. Mall-walking clubs, gym memberships, indoor low-impact aerobic classes, and senior-center Tai Chi classes may be viable alternatives for weight-bearing activities. Some individuals prefer aquatic exercise. However, deep-water walking would be considered a low-impact activity, whereas swimming would be considered nonimpact.1 

The American College of Sports Medicine recommends that individuals with osteoporosis avoid explosive activities such as jumping and running, which would place high-impact loads on the skeletal system.6 As these activities can produce an aerobic response, cardiac parameters should be monitored. Intensity can be measured via pulse rate or perceived exertion levels.

Resistance can be provided by many different methods, including free weights, weight machines, body weight, weighted vests, or exercise bands. Attention to proper form, posture, and body mechanics is critical to avoid injury.

Kisner and Colby outline many important precautions regarding resistance training in their textbook, Therapeutic Exercise: Foundations and Techniques.⁷ To prevent pathologic fractures, they recommend beginning weight training at low intensities and repetitions. Gradually progress intensity and volume. Perform most strengthening activities in weight-bearing positions with low to no impact. Avoid high-velocity movements. Avoid trunk flexion with rotation and other activities that could place excessive loading on the anterior aspect of the vertebrae. Avoid torsional movements of the hip in weight-bearing postures. And take measures to prevent balance loss or potential falls.7 This common-sense approach should help the PT establish a safe exercise prescription.

Many of our patients receive physical therapy for other conditions and have osteoporosis as a comorbidity. Many older patients are dealing with arthritis or spinal stenosis. Prescribing an appropriate exercise program for the spinal diagnosis can be challenging. With osteoporosis, there is the risk of developing a vertebral-compression fracture. Spinal-flexion exercises should be avoided, as they have been shown to promote compression fractures.8 

Postural and balance activities should be included in the exercise prescription. Proper posture and body alignment is critical to the management of osteoporosis. Incorporating visualizations to “think taller” can be very helpful.9 Using mirrors for visual feedback and tactile cuing can also help the patient improve his or her sitting and standing postures. Balance activities should be tailored to the patient’s current skill level and functional needs. Fall prevention should be stressed.

Throughout all activities, the patient should pay attention to correct body mechanics. The National Osteoporosis Foundation outlines “unsafe movements,” which would include twisting the spine or bending over from the waist with the legs extended.¹ These postures, which should be avoided during activities of daily living, can lead to vertebral fractures. The PT or occupational therapist should observe the patient during activities such as bed mobility, lifting, coughing, pushing, sitting, dressing, and reaching, and should make corrections as needed.¹

Resources

Many osteoporosis resources are available to both the PT and the health care consumer. The American Physical Therapy Association has a patient-education brochure titled What You Need to Know About Osteoporosis: A Physical Therapist’s Perspective.² The National Institutes of Health Osteoporosis and Related Bone Diseases-National Resource Center has many topics available, including Guidelines for Safe Movement.¹⁰ Many continuing-education courses for rehabilitation professionals are available across the United States. Many books and research articles have been published concerning this important topic. The National Osteoporosis Foundation (NOF) has a wealth of information available. It has also created a video called, Be BoneWise Exercise: NOF’s Official Exercise Video. This video includes a light-resistance exercise band and a safe-movement handbook. NOF does not recommend this video for those who are frail, have had a fracture, or fall frequently.¹¹

Osteoporosis management takes a team approach. The PT is an important member of that team. We can help our patients safely exercise and participate in functional activities. We can also encourage bone health for people of all ages through education and promotion of physical activity.

EDITOR’S NOTE: The references for this article are posted with the online version at www.PTProductsOnline.com.

Lisa Roberts, PT, MS, GCS, is a clinical assistant professor at Florida International University, Miami, where she teaches entry-level physical therapy courses. She is currently enrolled in a transitional DPT program at the University of St Augustine for Health Sciences, St Augustine, Fla. She has been certified as a geriatric clinical specialist since 1995. She can be reached at lroberts@fiu.edu.