E. S. Kruger, J. A. Hoopes , R. J. Cordial, and S. Li
-
Upload
rhoda-odonnell -
Category
Documents
-
view
15 -
download
0
description
Transcript of E. S. Kruger, J. A. Hoopes , R. J. Cordial, and S. Li
![Page 1: E. S. Kruger, J. A. Hoopes , R. J. Cordial, and S. Li](https://reader036.fdocuments.in/reader036/viewer/2022062720/56813590550346895d9cff38/html5/thumbnails/1.jpg)
Error compensation during finger force
production after one and four-finger
voluntarily fatiguing exercise.
E. S. Kruger, J. A. Hoopes, R. J. Cordial, and S. Li
By Kelsey Christensen
![Page 2: E. S. Kruger, J. A. Hoopes , R. J. Cordial, and S. Li](https://reader036.fdocuments.in/reader036/viewer/2022062720/56813590550346895d9cff38/html5/thumbnails/2.jpg)
• Motor Variability• Bernstein “repetition without repetition”.
Background
![Page 3: E. S. Kruger, J. A. Hoopes , R. J. Cordial, and S. Li](https://reader036.fdocuments.in/reader036/viewer/2022062720/56813590550346895d9cff38/html5/thumbnails/3.jpg)
• Motor Variability• Bernstein “repetition without repetition”.
• Degrees of Freedom (DOF)• Number of independent elements in a
system.
Background
![Page 4: E. S. Kruger, J. A. Hoopes , R. J. Cordial, and S. Li](https://reader036.fdocuments.in/reader036/viewer/2022062720/56813590550346895d9cff38/html5/thumbnails/4.jpg)
• Motor Variability• Bernstein “repetition without repetition”.
• Degrees of Freedom (DOF)• Number of independent elements in a
system.
• DOF Problem/Problem of Motor
Redundancy• How does the CNS select a particular
solution from the infinite number of
solutions?
Background
![Page 5: E. S. Kruger, J. A. Hoopes , R. J. Cordial, and S. Li](https://reader036.fdocuments.in/reader036/viewer/2022062720/56813590550346895d9cff38/html5/thumbnails/5.jpg)
Introduction• Error Compensation• DOFs work together to accomplish a
given task by compensating for
errors made.
• Utilizing motor variability and
redundant DOFs.
![Page 6: E. S. Kruger, J. A. Hoopes , R. J. Cordial, and S. Li](https://reader036.fdocuments.in/reader036/viewer/2022062720/56813590550346895d9cff38/html5/thumbnails/6.jpg)
Introduction• Error Compensation• DOFs work together to accomplish a
given task by compensating for
errors made.
• Utilizing motor variability and
redundant DOFs.
• How is error compensation
affected when parts of the
motor system are impaired
(number of DOFs is reduced)?
![Page 7: E. S. Kruger, J. A. Hoopes , R. J. Cordial, and S. Li](https://reader036.fdocuments.in/reader036/viewer/2022062720/56813590550346895d9cff38/html5/thumbnails/7.jpg)
Methods• Apparatus
• Procedures
• Data Analysis
![Page 8: E. S. Kruger, J. A. Hoopes , R. J. Cordial, and S. Li](https://reader036.fdocuments.in/reader036/viewer/2022062720/56813590550346895d9cff38/html5/thumbnails/8.jpg)
Methods• Apparatus
• Procedures
• Data Analysis
![Page 9: E. S. Kruger, J. A. Hoopes , R. J. Cordial, and S. Li](https://reader036.fdocuments.in/reader036/viewer/2022062720/56813590550346895d9cff38/html5/thumbnails/9.jpg)
![Page 10: E. S. Kruger, J. A. Hoopes , R. J. Cordial, and S. Li](https://reader036.fdocuments.in/reader036/viewer/2022062720/56813590550346895d9cff38/html5/thumbnails/10.jpg)
Methods• Apparatus
• Procedures
• Data Analysis
![Page 11: E. S. Kruger, J. A. Hoopes , R. J. Cordial, and S. Li](https://reader036.fdocuments.in/reader036/viewer/2022062720/56813590550346895d9cff38/html5/thumbnails/11.jpg)
Procedures• 13 young, healthy adults
• 2 sessions, 2-3 days apart• Index finger fatigued
• All four fingers fatigued
![Page 12: E. S. Kruger, J. A. Hoopes , R. J. Cordial, and S. Li](https://reader036.fdocuments.in/reader036/viewer/2022062720/56813590550346895d9cff38/html5/thumbnails/12.jpg)
![Page 13: E. S. Kruger, J. A. Hoopes , R. J. Cordial, and S. Li](https://reader036.fdocuments.in/reader036/viewer/2022062720/56813590550346895d9cff38/html5/thumbnails/13.jpg)
3 6 9
Force (N)
Time (s)
![Page 14: E. S. Kruger, J. A. Hoopes , R. J. Cordial, and S. Li](https://reader036.fdocuments.in/reader036/viewer/2022062720/56813590550346895d9cff38/html5/thumbnails/14.jpg)
3 6 9
Force (N)
Time (s)
![Page 15: E. S. Kruger, J. A. Hoopes , R. J. Cordial, and S. Li](https://reader036.fdocuments.in/reader036/viewer/2022062720/56813590550346895d9cff38/html5/thumbnails/15.jpg)
3 6 9
Force (N)
Time (s)
Ftot
FI
FM
FR
FL
Ftot = FI+ FM+ FR+ FL
![Page 16: E. S. Kruger, J. A. Hoopes , R. J. Cordial, and S. Li](https://reader036.fdocuments.in/reader036/viewer/2022062720/56813590550346895d9cff38/html5/thumbnails/16.jpg)
![Page 17: E. S. Kruger, J. A. Hoopes , R. J. Cordial, and S. Li](https://reader036.fdocuments.in/reader036/viewer/2022062720/56813590550346895d9cff38/html5/thumbnails/17.jpg)
Methods• Apparatus
• Procedures
• Data Analysis
![Page 18: E. S. Kruger, J. A. Hoopes , R. J. Cordial, and S. Li](https://reader036.fdocuments.in/reader036/viewer/2022062720/56813590550346895d9cff38/html5/thumbnails/18.jpg)
Data Analysis• Force signals from individual sensors to
analyze force profiles.
![Page 19: E. S. Kruger, J. A. Hoopes , R. J. Cordial, and S. Li](https://reader036.fdocuments.in/reader036/viewer/2022062720/56813590550346895d9cff38/html5/thumbnails/19.jpg)
• ΣVarFi = sum of the variances of
individual finger forces
• VarFtot = variance of total force
• Error Compensation Index (ECI) = ratio of
ΣVarFi to VarFtot.
From force profiles:
![Page 20: E. S. Kruger, J. A. Hoopes , R. J. Cordial, and S. Li](https://reader036.fdocuments.in/reader036/viewer/2022062720/56813590550346895d9cff38/html5/thumbnails/20.jpg)
Results
![Page 21: E. S. Kruger, J. A. Hoopes , R. J. Cordial, and S. Li](https://reader036.fdocuments.in/reader036/viewer/2022062720/56813590550346895d9cff38/html5/thumbnails/21.jpg)
• Variance (A) and Error Compensation Index (B) averaged over entire force ramp and across all subjects.
![Page 22: E. S. Kruger, J. A. Hoopes , R. J. Cordial, and S. Li](https://reader036.fdocuments.in/reader036/viewer/2022062720/56813590550346895d9cff38/html5/thumbnails/22.jpg)
• Average Error Compensation Index over the 1st, 2nd, and 3rd one-second segments of the ramp phase (seconds 4,5,6).
![Page 23: E. S. Kruger, J. A. Hoopes , R. J. Cordial, and S. Li](https://reader036.fdocuments.in/reader036/viewer/2022062720/56813590550346895d9cff38/html5/thumbnails/23.jpg)
Discussion
![Page 24: E. S. Kruger, J. A. Hoopes , R. J. Cordial, and S. Li](https://reader036.fdocuments.in/reader036/viewer/2022062720/56813590550346895d9cff38/html5/thumbnails/24.jpg)
Summary• The CNS is able to utilize the abundant
DOFs to compensate for motor system
impairments to maintain the desired
performance.
• Problem of Motor Redundancy is a GOOD
thing.
• Principle of Abundance – but there is a
limit.