Tendon lesions are a major problem in sports. They are difficult to treat as treatment may take months. Tendon injury is common due to low metabolism, blood and nutrient supply. Tendons respond to mechanical stresses by adapting its metabolism, structural and mechanical properties. Eccentric contraction occurs when the muscle tendon unit lengthens while a load or stress is applied producing the so called negative work. More force can be generated on tendon using eccentric contraction than in concentric or isometric contractions. Eccentric exercises have proved to be successful in the treatment of tendinopathy, especially in Achilles and patellar tendons. Although the site of the lesion affects its outcome. It can be done with as much forces as tolerated without increasing pain. It enhances collagen production and alignment, blood flow and activates mechanoreceptors leading to increase muscle tendon unit thus improve ROM. Eccentric exercises are based on 3 principles: 1-Length: It increases the resting length of muscle tendon unit which decreases strain occurring during joint movement. 2-Load: Increasing load on tendon increases tensile strength of the tendon. 3-Speed: increasing the speed will increase forces on the tendon. Example: Achilles tendon program in which the patient stands on a step with hind foot off the edge then the patient lowers his heel downward both bilateral and on one leg. Another example is the squats for patellar tendon on the ground and on a wedge on both legs or on single leg with and without knee flexion.
Plantar fascitis is characterized by pain at the calcaneal origin of the plantar fascia and increased thickness of the plantar fascia (Buchbinder, 2004). The condition is prevalent in both sports active and sedentary populations. The prevalence in the general population is estimated to range from 3.6% to 7% (Dunn et al., 2004; Hill et al., 2008), whereas plantar fasciitis may account for as much as 8% of all running-related injuries (Lysholm & Wiklander, 1987; Taunton et al., 2002). Many studies discussed the optimum treatment for plantar fasciitis and show that the treatment program should have a combination of passive and active techniques. Some clinical tips for plantar fasciitis management: 1. Patient education. 2. Advice the patient to wear comfortable shoes and reduce the activities that aggravate the symptoms. 3. Apply myofascial release, kinesio taping for pain management. 4. Manual therapy and strengthening exercise training to address any impairments identified during the objective assessment. 5. Gradual loading from double leg calf raises to single leg calf raises. 6. Apply Ratleff et.al loading program (2014): A. Single leg cuff raises with towel under the foot to increase the fascia loading. B. 3 secs concentric, 3 secs isomertic (pause), 3 secs eccentric. C. Loading could be increased by wearing a backpack or holding books. D. Apply the program for 12 weeks, 12 repetitions for 3 sets. 7- After completing the loading program, the patient can start a tailored sports program according to his tolerance. Read more about the High-load strength training in patients with plantar fasciitis https://www.ncbi.nlm.nih.gov/pubmed/25145882