Filed under: Joints
The physical demands placed on the Warfighter in training and operational settings can take a toll on joints and bones over time. Following a healthy diet can help reduce your risk of many diseases and maintain healthy joints and bones. A few nutrients have been shown to support joint and bone health, including calcium, vitamin D, vitamin C, and selenium. Consuming too much alcohol has been shown to have a negative effect.
Calcium and vitamin D work together for strong bones and overall bone health, because vitamin D helps your body absorb calcium. Men and women ages 19–50 should try to get 1000 mg of calcium daily; older women need 1200 mg daily. Good sources of calcium include milk, yogurt, fortified orange juice, and green leafy vegetables. Your body produces vitamin D when your skin is exposed to sunlight, but you can also get it in your diet from salmon, tuna, and fortified dairy products. Adults need about 600 IUs of vitamin D daily.
Vitamin C is essential for cartilage—the material that cushions your joints and prevents bones from rubbing together. Men need about 90 mg and women need about 75 mg daily, roughly the amount in a large orange. You can get vitamin C from citrus fruit, broccoli, and tomatoes.
Dietary selenium (a mineral) also may play a role in bone health. Adults need about 55 mcg of selenium daily. Selenium is found in nuts (especially Brazil nuts), tuna, and sunflower seeds.
Drinking too much alcohol negatively affects many of the body’s systems, including the bones and joints. Alcohol can cause weight gain, increase risk for osteoporosis and stress injuries, and damage cartilage. Limit your alcohol consumption to one drink per day for women and two for men. A drink is defined as one 5 oz. glass of wine, one 12 oz. beer, or one 1.5 oz. shot of liquor.
Inflammation can play a role in joint conditions such as arthritis, so a diet that helps reduce inflammation might be beneficial in protecting your joints. Eating plenty of fruits and vegetables, whole grains, and healthy fats (found in nuts and fatty fish such as salmon) not only reduces inflammation, it can also help maintain a healthy weight, which is essential to preserving joint health.
Excess body weight stresses joints and increases wear and tear. Following a diet that is lower in fat and calories can help maintain or reduce body weight, preventing additional joint stress. For more information about healthy joints, read the fact sheet from the National Institute of Arthritis and Musculoskeletal and Skin Diseases. Also, Chapter 17 of the Warfighter Nutrition Guide, “The High Mileage Warrior Athlete,” provides more information on maintaining joint and bone health.
Stretching and strengthening the muscles of the foot and ankle can help you prevent (and recover) from ankle sprains. The Foot and Ankle Conditioning Program from the American Academy of Orthopaedic Surgeons focuses on recovering from injury, but it includes well-illustrated exercises that are good for preventive conditioning too. Here are some other exercises useful for strengthening the foot and ankle structure:
- From a seated position, “pretend” writing the alphabet with each foot, in both upper- and lower-case letters.
- Stand on one leg on a pillow for 10 seconds and then switch legs. Be sure to have something nearby to grab for balance if necessary.
- From a seated position, use a resistance band looped to a secure surface, and wrap the other end around your forefoot; then move your foot/ankle forward, backward, and side-to-side, flexing at the ankle.
An ankle sprain involves damage to ligaments—bands of tissue that help hold joints together—in the foot and ankle, usually from the force of landing wrong on your foot. In military populations, ankle sprains are very common, significantly affecting operational readiness. In fact, ankle sprains are more common in the military than in civilian populations and more likely among women than men. By strengthening the muscles in your legs and feet, you can give more support to your ankle in the event of a misstep or an encounter with uneven terrain. The transition from military boots, which offer more ankle support, to traditional athletic shoes may also leave you and your ankles feeling vulnerable to twists and sprains. Start including ankle-strengthening exercises into your daily workout routine to help keep your ankles strong and free from injury.
Being overweight puts you at risk for a whole host of health issues, but most people don’t think about the risk posed to their knees. The anterior cruciate ligament, or ACL, is one of the major ligaments of the knee and one of the most susceptible to injury. Injury information on more than 1,600 men and women at the U.S. Naval Academy showed that those with a higher body mass index (BMI) had a greater incidence of ACL tears. A difference in BMI of only 1.2 (25.6 versus 24.4) made the difference between having and not having this kind of injury. (To learn more about BMI, read HPRC's explanation.)
Like the adage “You don’t know what you’ve got until it’s gone,” knees are something we generally take for granted. To stay on top of your game, you need your knees. An easy way to protect them is to drop the extra weight you’re asking them to carry around.
Your body is a segmented, or jointed, system designed for potentially powerful and efficient movement. Coordinated and efficient movements require a give and take between mobility and stability of the involved joints, as well as the surrounding muscles, tendons, and ligaments. These components, together with muscular fitness, are necessary to achieve functional movement, which is integral in performance and sport related skills.
According to the American Council on Exercise (ACE), joint mobility—also known as range of motion (ROM)—is the degree to which a joint is able to move before it is restricted by surrounding ligaments, muscles, and tendons. Joint stability is the ability to control or restrict joint movement through the coupled actions of surrounding tissues. Preventing injuries requires, among other things, both mobility and stability of your musculoskeletal system. Deficiencies in one or the other, due to improper or imbalanced training, may lead to injuries during movement patterns, such as walking, running, and repetitive lifting.
One example of an elite training program is the Army Ranger RAW functional fitness program. It is unique in that it focuses on whole-body mobility and stability. Exercises are typically performed using your own body weight against fixed surfaces (i.e. the floor or wall), instead of using free weights or machine weights.
For joint stability and balance, the National Academy of Sports Medicine (NASM) recommends performing one to three sets of 12-20 repetitions at a slow, controlled pace. According to American College of Sports Medicine (ACSM), there is not enough research to make definitive recommendations on the frequency and duration for this type of training. However some research has shown improvements using training frequencies of 2-3 days per week, with sessions lasting ≥20-30 minutes, for a total of ≥60 minutes per week.
The amount of joint mobility is partially determined by the flexibility of the surrounding muscles, tendons, and ligaments. For example, decreased shoulder flexibility might impact your ability to complete a full pushup. Refer to these FITT guidelines for flexibility training.
Frequency: According to ACSM, short-term improvements in flexibility may be seen after each bout of stretching. More long-term changes, however, are seen after three to four weeks of regular stretching. Flexibility exercises should be performed at least two to three days per week, but daily exercise will improve range of motion.
Intensity: ACSM also recommends that flexibility exercises should involve major muscle groups (neck shoulders, upper and lower body), stretching to the point of slight discomfort within the range of motion, but no further. You should feel slight tension in the muscle, but it should not be painful.
Type: There are several different types of stretches:
• Static stretching slowly elongates a muscle by holding the position for a period of time.
• Dynamic stretching is usually sport specific. It requires a joint to be stretched through its full range of motion, to lengthen and increase the muscles temperature.
• Ballistic stretching is a type of dynamic stretch where the muscle is forcefully elongated through a bouncing motion. There’s no evidence that ballistic stretching results in injury, but there is still question and ongoing research as to whether this technique affects muscular performance.
• Proprioceptive Neuromuscular Facilitation or PNF stretching may produce greater gains in ROM, however, it may be less practical since an experienced partner is needed to perform this type of exercise.
Time: Your stretching routine should take about ten minutes or so to complete. Static stretches should be held for 15-20 seconds, while PNF stretches should involve a six-second contraction followed by a 10- to 30-second assisted stretch.
Use caution when working on mobility and stability exercises. Done properly, these exercises should not cause pain in the joint or muscle. Never push through your threshold, have patience, and treat your joints with care.