An improved device to measure human response to dorsiflexion and plantar flexion perturbations

[摘要] ENGLISH ABSTRACT: The Dorsiflexometer is a device designed and built for the assessment of apatient's balance capabilities. The birth of the Dorsiflexometer is due to aserious need for physiological balance assessment equipment, capable of conductingdynamic tests in the clinical setting. This is accomplished by recordingand analysing the patient's response to sagittal plane perturbations. The Dorsiflexometeris operated from a computer software interface program. It usesthe measurements from a single force plate to calculate four balance metrics'characterising a patient's ability to maintain balance. These balance metricsinclude the sway index, equilibrium score, postural stability index and radiusparameter.A single and a double inverted pendulum model of the human body is derivedto calculate a patient's centre of mass movement in the sagittal planewith the measured force plate data and body parameters. Three experiments,involving 48 subjects, were conducted. The experimental tests proved thecompetency of the machine, the accuracy of both inverted pendulum modelsand the balance response of seafarers aboard an Antarctic research and supplyvessel during rough sea conditions.The tests concluded that the inverted pendulum models can be used to calculatethe body centre of mass displacement. The double inverted pendulummodel results are more accurate compared with the single inverted pendulummodel. During rough sea conditions, the body movement and posturalresponse of seafarers are increased in order to keep themselves upright. Thebody is furthermore exposed to a fluctuating ground reaction force which maylead to the progression of osteoarthritis and musculoskeletal injuries. The Dorsiflexometerproved to be capable of conducting repeatable assessments and yielding accurate results which can be used to distinguish between balancecapabilities.

[发布机构] Stellenbosch University