·Table of Contents ·General | Testing Vibration Analysis of the Achilles Tendon StateAuthorMaslov Leonid Borisovich PhD, Professor 34 Rabfakovskay Str., Ivanovo, 153548, Russia Theoretical and Applied Mechanics Department State Power University of Ivanovo Tel., (0932)38-57-84 Fax: (0932)38-57-01 E-Mail: ispu@iname.com (for L.B. Maslov) Co-Authors Shapin Vadim Ivanovich PhD, Professor 34 Rabfakovskay Str., Ivanovo, 153548, Russia Theoretical and Applied Mechanics Department State Power University of Ivanovo Tel., (0932)38-57-84 Fax: (0932)38-57-01 Korablev Stanislav Sergeevich DrS, Professor 34 Rabfakovskay Str., Ivanovo, 153548, Russia Theoretical and Applied Mechanics Department State Power University of Ivanovo Tel., (0932)38-57-84 Fax: (0932)38-57-01 Contact |
Keywords: achilles tendon, tear, vibration, resonance, diagnostics.
1) Alterations of frequency-resonance range of the tendon-muscular complex in the injured and contralateral (healthy) extremity in flexion (bending), extension (straightening) and neutral foot position:
where W^{s0}_{inj} , W^{s0}_{c/lat }- difference of resonance frequencies in foot straightening and in neutral foot position for the injured and contralateral extremities; W^{sb}_{inj} , W^{sb}_{c/lat} - difference of resonance frequencies in foot straightening and in foot bending for the injured and contralateral extremities:
where W^{s} , W^{0 }, W^{b} - resonance frequencies in foot straightening, neutral and bending position for injured and contralateral extremeties (indexes "_{inj}" and "_{c/lat}" are not written for simplicity here and below) (Fig.2).
Fig 2: Recorded amplitude-frequency characteristics of the Achilles tendon-muscle system of the patient A.V.K-y, case-history #51, 30 days after breaking, distance from the calcaneus tubercle - 3 sm, tendon edges divergence (diastasis) - 2 sm, scar tissue in the tear area. |
Diagnostic sign - is the narrowing of the resonance-frequency range in the following foot positions: extension-neutral and extension-flexion:
2) Alterations of amplitude-resonance range of the tendon-muscular complex in the injured and contralateral (healthy) extremity in flexion (bending), extension (straightening) and neutral foot position:
DA^{0b }= (A^{0b}_{inj} - A^{0b}_{c/lat }) / A^{0b}_{c/lat },
where A^{s0}_{inj} , A^{s0}_{c/lat }- difference of resonance amplitudes in foot straightening and in neutral foot position for the injured and contralateral extremities; A^{0b}_{inj} , A^{0b}_{c/lat} - difference of resonance amplitudes in neutral and bending foot position for the injured and contralateral extremities:
where A^{s} , A^{0 }, A^{b} - resonance amplitudes in foot straightening, neutral and bending position for injured and contralateral extremeties (Fig.2).
Diagnostic sign - is the narrowing of the extension-neutral amplitude range and the rise of the neutral-flexion amplitude range:
4) Alterations of the quantity of peaks on the resonance curves in the injured and contralateral (healthy) extremity in flexion (bending), extension (straightening) and neutral foot position:
Dn^{0 }= (n^{0}_{nj} - n^{0}_{c/lat }) / n^{0}_{c/lat } ,
D n^{s }= (n^{s}_{inj} - n^{s}_{c/lat }) / n^{s}_{c/lat } ,_{ }
where n^{b}_{inj} , n^{b}_{c/lat }, n^{0}_{nj} , n^{0}_{c/lat }, n^{s}_{inj} , n^{s}_{c/lat }- the number of peaks on the resonance curves in every foot position for the injured and contralateral extremities.
Diagnostic sign - smoothing of the resonance curve and decrease in the number of resonance peaks in the every foot position:
This sign is theoretically observed as smoothing of the numerically calculated AFC curves.
Reliability of presence of the tendon tear can be characterised by the total percent sum in all the diagnostic signs (or intencity S) which is calculated by the formulas:
The higher this magnitude is, the more reliable is the Achilles tendon tear.
Table 1: The Achilles tendon resonance curves parametres for the clinical cases |
Fig 1: Recorded amplitude-frequency characteristics of the Achilles tendon-muscle system of the patient S.V.B-v, case-history #60, 2 days after breaking, distance from the calcaneus tubercle - 5 sm, tendon edges divergence (diastasis) - 1 sm, space in the tear area is occupied by a haemorrhage. |
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