systems, offers a unique case for the elderly. The high-force and low-cost set of attributes in eccentric exercise makes it ideal for the actively impaired. Muscle tendon injuries The entire muscle-tendon system works cohesively to slow down limb movement. The close relationship between the muscle and tendons help to dissipate heat or temporarily store kinetic energy. If the forces needed to slow down a limb exceed the capacity of the muscle-tendon system, injury is likely to occur. Athletes with recurring hamstring and abductor muscle injuries have greater impairment of eccentric strength, suggesting that improvements in eccentric training may minimize the risks of injury by strengthening the muscle-tendon groupings in high-stress areas of the body. Eccentric training is of huge benefit to those that wish to avert injuries by improving the muscles abilities to absorb more energy before deteriorating. According to one article, "Increased stiffness in tendons, greater force at failure, and an improved ability to absorb energy at the musculotendonous junction result following eccentric exercise training". Osteopenia Usually viewed as a precursor to osteoporosis, osteopenia is when bone density is lower than normal levels. Bone mass is affected by muscles forces and their loads to the bone structure. The strength and density of the bone is directly influenced by local strain. Due to the high strain on muscles during eccentric training, coupled with low energy output, eccentric training becomes a cornerstone of the rehabilitative process. Tendinoses Intense repetitive activities tend to create chronic tendon disorders, where the tendons become injured, inflamed or ruptured. While typically these disorders are directly related to eccentric muscle movements, the ability for a muscle to strengthen and prevent injury through eccentric training is great. Controlled rehabilitative regimes will actually strengthen and repair tendons. Ample evidence supports the notion that the tendon, like the muscle, can adapt favorably to physical stress and eccentric loads. It has been deduced that high muscle tendon forces delivered in a controlled environment are needed for optimal tendon adaptation. While eccentric stress is related to the injury, high force eccentric exercises are needed to maximize recovery. Chronic patellar tendonitis A condition that arises when the tendon and the tissues that surround it, become inflamed and irritated. This is usually due to overuse, especially from jumping activities. This is the reason chronic patellar tendonitis is often called "jumper’s knee." A study done by Roald Bahr and colleagues looked at which method of