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An Instrumented Pull Test to Characterize Postural Responses
Published on: April 6, 2019
Postural feedback scaling deficits in Parkinson's disease
Seyoung Kim1, Fay B Horak, Patricia Carlson-Kuhta
1Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, 335 Gwahak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea. sukyungp@kaist.ac.kr
Journal of Neurophysiology
|September 11, 2009
Summary
Researchers developed a model to explain age and Parkinson's disease (PD) effects on balance. PD patients exhibit abnormal feedback gains, leading to smaller, bradykinetic postural responses and balance challenges.
Area of Science:
- Biomechanics
- Neuroscience
- Systems Biology
Background:
- Ageing and Parkinson's disease (PD) significantly alter postural responses.
- Previous research lacked quantitative models to explain these postural differences.
- Understanding these changes is crucial for developing targeted interventions.
Purpose of the Study:
- To develop a quantitative feedback control model of body dynamics.
- To reproduce and explain postural responses in young, elderly, and PD subjects.
- To investigate if PD-related postural impairments stem from abnormal postural feedback gain scaling.
Main Methods:
- A feedback control model of body dynamics was created.
- Seven subjects each from young, elderly, and PD groups experienced controlled postural perturbations.
- Ground reaction forces and joint kinematics were measured; joint torques were derived via inverse dynamics.
Main Results:
- All groups scaled postural feedback gains with perturbation amplitude.
- PD subjects displayed significantly reduced ankle feedback gain and impaired scaling.
- PD subjects showed increased hip feedback gain, leading to early balance loss and bradykinetic responses.
Conclusions:
- The model quantitatively describes PD postural abnormalities as abnormal feedback gains.
- PD patients have a reduced capacity to adjust postural feedback gain under varying challenges.
- Findings highlight the role of feedback control deficits in PD-related balance impairments.
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