1997 Fiscal Year Final Research Report Summary
The pathogenesis of the functional instability of the ankle
| Project/Area Number |
08457378
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Orthopaedic surgery
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| Research Institution | University of Tsukuba |
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Principal Investigator |
ISHII Tomoo University of Tsukuba, Clinical Medicine, Orthopaedic Surgery, Assistant Professor, 臨床医学系, 講師 (70272193)
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| Project Period (FY) |
1996 – 1997
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| Keywords | Functional Instability of the Ankle / Peroneal Reaction Time / Stability Index / Mechanoreceptor |
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| Research Abstract |
The characteristic of functional instability (FI) of the ankle is the sense of instability. Its pathogenesis is still uncertain. Imbalance on the balance board and delay of the peroneal reaction time (PRT) are known as the examinations of FI.Biodex Stability System can measure a quantity of the imbalance as Stability Index (SI). We examined the patients with the FI by using SI and PRT.
SI means the integration of the deviation from the center of gravity. Large quantity of SI means poor balance. The patients' mean SI was 2.2, and the controls' was 2.1 (not significant). The patients' mean PRT was 90.1 msec and significantly delayd from the controls' 72.1 msec. About he relation between SI and PRT,there was plus relation (r=0.677) in controls however no relation in patients. We considered while both PRT and SI reflected the extent of FI,SI was easier to control by other compensation mechanism than PRT and the compensation worked to become stable in the patients.
Many patients with FI often complain a pain at the sinus tarsi, where the ligaments that support the ankle and nerve terminals lie. Their senses of instability usually disappear by an injection of local anesthetic into the sinus tarsi. In such patients, We measured PRT before and after the injection. The mean PRT in controls didn't change the value (71.8 msec) both before and after the injection. On the contrary, the mean PRT in the patients was significantly delayd (79.8 msec) before the injection, which became to normalize (68.9 msec) after it. Disappearance of the sense of instability and normalized PRT happened simultaneously in patients after the injection. We concluded peripheral nerve signal around the ankle may cause the FI and our data disagree to the mechanoreceptor (deficit) theory.
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Research Products
(2 results)
