Sensor location affects skeletal muscle contractility parameters measured by tensiomyography

Tensiomyography (TMG) is a non-invasive method for measuring contractile properties of skeletal muscle that is increasingly being used in research and practice. However, the lack of standardization in measurement protocols mitigates the systematic use in sports medical settings. Therefore, this study aimed to investigate the effects of lower leg fixation and sensor location on TMG-derived parameters. Twenty-two male participants underwent TMG measurements on the m. biceps femoris (BF) in randomized order with and without lower leg fixation (fixed vs. non-fixed). Measurements were conducted at 50% of the muscle’s length (BF-mid) and 10 cm distal to this (BF-distal). The sensor location affected the contractile properties significantly, both with and without fixation. Delay time (Td) was greater at BF-mid compared to BF-distal (fixed: 23.2 ± 3.2 ms vs. 21.2 ± 2.7 ms, p = 0.002; non-fixed: 24.03 ± 4.2 ms vs. 21.8 ± 2.7 ms, p = 0.008), as were maximum displacement (Dm) (fixed: 5.3 ± 2.7 mm ..., A single-group randomized-crossover design was used for this study, which was approved by the local ethics committee (#) and conducted in accordance with the ethical standards set by the declaration of Helsinki. Skeletal muscle contractility of the biceps femoris (BF) of the dominant leg was assessed using tensiomyography (TMG; TMG-BMC Ltd., Ljubljana, Slovenia). The participants lay in a prone position with their ankles placed on the TMG cushion for lower leg measurements, so that the measurement was performed with a knee flexion of about 5°. The TMG measurements were performed at two measurement sites and conditions on the BF. The first measurement site was at 50% of the length between the origin (ischial tuberosity) and the insertion (head of the fibula) (BF-mid); the site was marked with a water-resistant pen. To ensure that the mark was correctly placed on the BF, each participant was instructed to perform an isometric contraction with the hamstrings at 90° knee flexion against the..., Microsoft Excel