Abstract: Tendinopathy characterized by overuse and overloading is a common injury in athleticpopulations. Eccentric contraction is believed as an extrinsic risk factor to acute or chronictendinopathy. Adverse effects of acute eccentric contractions on the tendon, includingdecrease mechanical properties and increase microcirculation, may jeopardize the tendon andlead to a following tendinopathy. The objectives of this three-year research project are 1-1) toinvestigate effects of repetitions of maximal eccentric contractions of knee extension onmechanical properties (tendon stiffness) and microcirculation (total hemoglobin and oxygensaturation) of the patellar tendon. Furthermore, correlations between changes of themechanical properties and microcirculation are analyzed; 1-2) to study effects of intervalintervention during the eccentric contractions on the tendon properties and microcirculation; 2)to evaluate the effects of physical agents on microcirculation of the Achilles tendon; 3) toelucidate the microcirculation of the early stage of repaired Achilles tendon. In addition,correlation between microcirculation results of early stage and the mechanical properties inthe late stage after repair surgeries are assessed.In the first year, 45 male subjects, aged from 20 to 45 years old, are going to be recruitedand randomized assigned into three groups (4sets of 60 repetitions at a speed of 60 degree persecond, 4 sets of 80 repetitions at a speed of 60 degree per second, and 4sets of 80 repetitionswith intervention) to determine whether the repetitions of maximal eccentric contractionshave significant effects on the tendon properties and microcirculation in their dominant leg. Inaddition, whether the effects of the maximal eccentric contractions can be attenuated byprophylactic intervention, such as submaximal isometric contraction, between sets of theeccentric contractions is also investigated. In the second year, effects of physical modalities(including ultrasound, low power laser, interferential current and vibration) on the tendonmicro-circulation in the Achilles tendon in both (dominant and non-dominant sides) legs areinvestigated in subjects, aged from 20 to 45 years old. These modalities are applied on themiddle portion of the Achilles tendon or muscle belly of the calf muscles, and the tendonmicrocirculation is measured before and after the applications. In the third year, 20 malesubjects with a unilateral Achilles repair are going to be recruited. Microcirculation will beassessed in the 1st, 2nd and 3rd month after the repair. Furthermore, tendon mechanicalproperties and functional performances are assessed in the 3rd and 6th month after the repair.Results of this current study are going to 1) confirm the effects of repetitions of maximaleccentric contractions on tendon mechanical properties and microcirculation in the patellartendon; 2) confirm there is a correlation between acute changes of tendon mechanicalproperties and microcirculation; 3) assess prophylactic effects of submaximal isometriccontraction within the maximal eccentric contractions; 4); determine the effects of physicalmodalities on microcirculation of the Achilles tendons; 5) elucidate the characteristics oftendon microcirculation early after Achilles repair (<3 month) and study correlations betweenmicrocirculation and mechanical properties in the late stage of repairs of tendon surgery.
肌腱修補tendon mechanical property