Validating the Speckle Tracking Methods on Soft Tissue Strain, Displacement, and Roles in Physical Therapy

Inclusion Criteria: Study 1 * male pitchers aged between 18 and 35 years * more than five years of pitching experience * at least 200 counts of pitching training per week Study 2 * Age between 20 and 65 years * diagnosed with grade II posterior tibial tendon dysfunction and recommended by a physician for surgical intervention Study 3 * The participants were between 18 and 45 years old * had undergone unilateral anterior cruciate ligament semitendinosus tendon autograft reconstruction surgery within the past 6 years * were able to fully participate in the sports and training they had before their injury Exclusion Criteria: Study 1 * diagnosed with partial or full thickness tears of the UCL by arthrographic/ nonarthrographic MR techniques in past medical records * having a positive result in the "moving valgus stress test" screening24 * unable to participate in regular baseball pitching training or absent from the competition during the March 2023 to March 2025 season * found to show suspicious signs, such as hypoechoic foci and calcification, which suggest UCL injury under ultrasound screening4 * with a \<80% compliance rate in the eight-week BFRT Study 2 * The lower extremities have undergone surgical intervention * The lower extremities have a known history of nerve or vascular injury * The ankles and feet have known ligament tears * Fixed deformities of the foot joints * The patient has a known physical condition that would affect the conduct of the experiment Study 3 * Having any orthopedic condition that prevents them from participating in the competition, such as arthritis or knee pain * having a history of hamstring muscle strain in the knee within the past 3 months * having an attendance rate of less than 80% in the subsequent eight weeks of training