Due to technological limitations several aspects of the musculoskeletal system are still largely hidden to researchers and clinicians when trying to unravel the internal dynamics of locomotion. To still be able to quantify velocities and forces in muscle and tendon tissues, locomotion researches help themselves by using inverse approaches.
In simple words: First scientist evaluate material parameters of muscle and tendon tissues e.g. by testing cadavers. Second, they record locomotion (joint angles and forces) from an outside – camera angle – perspective. Finally, with the knowledge of body anthropometries, geometrical functions, contact forces and material parameters they are able to estimate velocities and forces that occur inside the body (eg., in muscles and tendons).
But there is a known snag! This approach presumes that the behaviour of living tissues is linear and scalable. A proven bias which is widely accepted in science due to the lack of technology to investigate better.
But how to improve from here?
In contrast to other tissue imaging techniques such as MRI or CT, Ultrasound is a promising methodology that enables real time, in-vivo, radiation free views on the muscle-tendon behaviour during human and animal locomotion. Recording the highly non-linear behaviour of muscles and tendons using ultrasound is still limited but there are recent technological advances that can be leveraged for biomechanics applications.
A team of researchers consisting of biomedical, ultrasound and microelectronics engineers as well as human and equine movement scientists have reviewed current ultrasound applications in locomotion research and provided a list of recommendations for a new ultrasound system class targeting biomechanics application.
Find full open-access research here: https://doi.org/10.3390/s19194316