Two experiments were performed to provide evidence for the validity of using an
intermittent fatigue test paired with MMG, measured as skin surface acceleration, to
detect functional changes in the muscle. During the first experiment, acceleration data
was collected on 6 subjects using an
Axivity AX3 triaxial accelerometer (Axivity:
Newcastle, UK) and was correlated to torque measurements recorded simultaneously using a
Cybex Humac Norm Dynamometer (Cybex: Bayreuth, Germany). The second experiment was
performed to determine whether the MMG data collected during the proposed fatigue test
would detect reduced muscle function when it should be present. A separate set of subjects
(
n = 10) was recruited for this second experiment. Subjects performed
two fatigue tests (control vs tourniquet) each for both the ankle dorsiflexors (AD) and
the wrist extensors (WE) as described below. Tourniquet trials were assigned in a
counterbalanced design, with half the subjects performing the tourniquet trials first and
the other half performing them during the second trial. Subjects had a 10-min break
between trials to allow the muscle time to recover.
Brandenberger K.J., Rawdon C.L., Armstrong E., Lonowski J, & Cooper L. (2023). A non-volitional skeletal muscle endurance test measures functional changes associated with impaired blood flow. Journal of Rehabilitation and Assistive Technologies Engineering, 10, 20556683231164339.