The effects of 6-week home-based static stretching, dynamic stretching, or eccentric exercise interventions on muscle-tendon properties and functional performance in older women.

"Declaration of competing interest The authors declare no conflict of interest."

"Funding The present study was fully financially supported by the Allied Health Sciences Research Fund and partly by the Burapha University Research and Development Fund."

"The study design was a randomized, double-blinded clinical trial, adhering to the guidelines outlined in the CONSORT 2010 flow diagram. (). The study protocol was registered on the Thai Clinical Trials Registry (TCTR) identification number of TCTR20230321013. A few days before the interventions, all participants undertook a familiarization session at the Physical Therapy Department, Allied Health Science Faculty, Burapha University. They were randomly assigned to three interventional exercise groups [dynamic closed-chain stretching (DCS), eccentric exercise (ECC), and static stretching (ST)] by blocks of six randomizations using sealed, numbered, and opaque envelopes. The procedure of categorizing participants into groups was based on age similarity, serving as the principal confounding criterion in this study. The musculotendinous ultrasound imaging and stiffness, flexibility, and eccentric strength variables served as primary outcomes, with functional performance considered as a secondary outcome. All measurements were made by the same investigators in the same order at pretraining, two days after 6 weeks of training, and at 1 month detraining follow-up. The selected timing of assessments was based on the standard 6–12-week cycles typically associated with flexibility and strength training, while de-adaptation can be apparent after as short as 4 weeks. The primary investigators did not know which program the participant was assigned to, and the participant was unaware of the details of the other intervention programs.Fig. 1The study flowchart.Fig. 1"