Skeletal muscle operates as a near-constant volume system; as such muscle shortening during contraction is transversely linked to radial deformation. Therefore, to assess contractile properties of skeletal muscle, radial displacement can be evoked and measured. Mechanomyography measures muscle radial displacement and during the last 20 years, tensiomyography has become the most commonly used and widely reported technique among the various methodologies of mechanomyography. Tensiomyography has been demonstrated to reliably measure peak radial displacement during evoked muscle twitch, as well as muscle twitch speed. A number of parameters can be extracted from the tensiomyography displacement/time curve and the most commonly used and reliable appear to be peak radial displacement and contraction time. The latter has been described as a valid non-invasive means of characterising skeletal muscle, based on fibre-type composition. Over recent years, applications of tensiomyography measurement within sport and exercise have appeared, with applications relating to injury, recovery and performance. Within the present review, we evaluate the perceived strengths and weaknesses of tensiomyography with regard to its efficacy within applied sports medicine settings. We also highlight future tensiomyography areas that require further investigation. Therefore, the purpose of this review is to critically examine the existing evidence surrounding tensiomyography as a tool within the field of sports medicine.

The aim of this study was to examine the concurrent validity of 2 portable systems for vertical jump (VJ) assessment under field conditions. The VJ flight times assessed using an optical mat (Optojump) and an accelerometer-based (Myotest) system were compared with that of a force platform. The flight times recorded during a countermovement jump (CMJ) were collected from 20 rugby players (n = 86 jumps) concurrently using the 3 tracking systems. Significant bias between the Force platform and either the Optojump (bias = 0.006 ± 0.007; 95% confidence interval [CI] 0.004-0.007 seconds) and Myotest (bias = -0.031 ± 0.021; 95% CI 0.035 to -0.026s; p < 0.0001) occurred. A nearly perfect correlation was found between force platform and Optojump (r = 0.99; 95% CI 0.098-0.99; p < 0.0001). Force platform and Myotest (r = 0.89; 95% CI 0.084-0.93; p < 0.0001) flight times showed very large association. Difference between Optojump and Myotest systems was significant (-0.036 ± 0.021 seconds; 95% CI -0.041 to -0.032; p < 0.0001), which results in Myotest mean flight time being approximately 7.2% longer than the Optojump flight time. The association between Optojump and Myotest was nearly perfect (r = 0.91, 95% CI 0.86-0.94; p < 0.0001). This study showed that the Optojump and Myotest systems possess convergent validity and can be successfully used under field conditions to assess VJ while performing a CMJ. However, caution should be exercised when interpreting data obtained from different portable systems for field measurement.

No abstract

Portable tensiomyography and myotonometry devices have been developed to measure mechanical and contractile properties of skeletal muscle.The aim of this study was to explore the sensitivity of the aforementioned techniques in detecting a change in passive mechanical properties of the biceps femoris muscle (BF) as a result of change in knee joint angle (i.e. muscle length).BF responses were assessed in sixteen young participants (23.4±4.9 years), at three knee joint angles (0, 45, and 90 degrees), for maximal isometric torque (MIT) along with myoelectrical activity. Contractile and mechanical properties were measured in a relaxed state. Inter-day reliability of the tensiomyography and myotonometry was also assessed.MIT changed significantly (p<0.01) across the three angles, so did stiffness and other parameters measured with myotonometry (p<0.01). Conversely, tensiomyography could detect changes only at two knee angles (0 and 45 deg, p<0.01), when there is enough tension in the muscle. Reliability was overall insufficient for tensiomyography whilst absolute reliability was excellent (CV < 5%) for myotonometry.The ability of myotonometry more than tensiomyography to detect an inherent change in stiffness can be conceivably exploited in a number of clinical/therapeutic applications that have to do with unnatural changes in passive muscle stiffness.

This study provides some insight into potential mechanisms by which an eccentric hamstring exercise programme utilizing the NHE as the mode of exercise may result in an improvement in hamstring muscle control during eccentric contractions.