Wearable Shear Wave Tensiometry for Tracking Tendon Load during Dynamic Movement

Project Summary The long term goal of this project is to develop a wirelesswearable system to estimate the tension in tendons of the legs during dynamic movementsTendon tension provides an estimate of muscle forcewhich is important information for understanding biomechanical behavior in all types of movementthough it has previously been difficult to measureRecent advances have shown that skin mounted accelerometers can track the propagation of shear waves along a tendonafter the waves are induced by a light mechanical tap on the tendonThe speed of wave propagation depends on the tension in the tendonso measuring wave speed provides a measurement of tendon tensionThe proposed project will build and test a wearable system to make these tendon tension measurements during free movementThese measurements promise to enable new methods of injury assessmentrehabilitationathletic trainingand treatment of musculoskeletal disordersThis research will investigate the ability of a mobile system to make measurements that match the quality of laboratory systemsand the ability of tendon tension measurements to provide insight into biomechanics during movement in everyday environmentsThe Specific Aims of this project are toTo designbuildand validate a wearable system for measuring tendon tension through measurements of shear wave propagation speed in tendonTo investigate the utility of wearable tendon tension measurements for assessing biomechanical function during real world activities Project NarrativePublic Health RelevanceKnowledge of muscle forces is critical for understanding coordinationenergy consumptionand injuryfor quantifying responses to interventions such as surgery or rehabilitationfor improving performance in demanding biomechanical tasksand for designing biomechanical devices such as rehabilitation equipment and robotic exoskeletonsUnfortunatelymost current techniques for estimating muscle force are indirect and reliant on complex modeling assumptionsThe direct measurement of in vivo muscle tendon forces has remained one of the great unsolved biomechanics problemsWe recently discovered that the propagation speed of shear waves in tendon can be used to infer tendon tensionand invented a simple skin mounted probe to measure this wave speed noninvasivelyThe proposed research program aims to develop this laboratory based tendon tensiometry technology into a wearablewireless commercial system that can be used anywhereThe advent of a field based tendon tensiometry system has the potential to catalyze many further scientific and technological advancementssuch as estimating in activity muscle tendon force and energy consumptionresolving muscle redundancy in biomechanical modelsassessing neuromusculoskeletal disordersproviding biofeedback for rehabilitationand controlling human collaborative robots