Deep digital flexor tendon force and digital mechanics in normal ponies and ponies with rotation of the distal phalanx as a sequel to laminitis

M P McGuigan, T C Walsh, C H Pardoe, P S Day, A M Wilson

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

Reasons for performing study: Previous studies have implicated tension in the deep digital flexor tendon (DDFT) in the rotation of the distal phalanx (DP) after the breakdown of the dorsal laminae caused by laminitis. Howeveer, once the DP has rotated, the DDFT should become shorter, reducing the force it exerts on the DP. Objective: To compare DDFT force and ground reaction forces (GRFs) in normal ponies and ponies with rotation of the DP as a sequel to laminitis. Methods: Six normal ponies (Group 1) and 6 sound ponies with 6-13degrees of rotation of the DP in relation to the dorsal hoof wall (Group 2) were assessed at trot using forceplate and motion analysis. The force in the DDFT was calculated by assuming that the extending moment at the distal interphalangeal (DIP) joint resulting from the GRF was equal to the flexing moment created by the force in the DDFT during the stance phase (inverse dynamics). Results: In early stance, the peak DDFT force (mean +/- s.d.) in the normal ponies was 1.92 +/- 1.63 N/kg. However, in Group 2, the point of zero moment was palmar to the centre of rotation of the DIP joint for the first 40% of stance and hence DDFT force was zero. Force in the DDFT reached a peak of 10.00 +/- 3.56 N/kg at 60.7 +/- 5.6% of stance in Group 1 and 6.41 +/- 1.37 N/kg at 79.2 +/- 9.6% of stance in Group 2. Conclusions: DDFT force in Group 2 laminitic ponies was much reduced until late stance, when it neared normal values. Potential relevance: Further studies of ponies with rotation of the DP as a sequel to laminitis should assist farriery aimed at reducing the force in the DDFT through the breakover phase of stance to protect damaged dorsal laminae.
Original languageEnglish
Pages (from-to)161-165
Number of pages5
JournalEquine Veterinary Journal
Volume37
Issue number2
Publication statusPublished - 2005

Fingerprint

laminitis
phalanges
tendons
Mechanics
mechanics
Tendons
horses
laminae (animals)
joints (animal)
Joints
Hoof and Claw
hooves
normal values
Reference Values

Cite this

Deep digital flexor tendon force and digital mechanics in normal ponies and ponies with rotation of the distal phalanx as a sequel to laminitis. / McGuigan, M P; Walsh, T C; Pardoe, C H; Day, P S; Wilson, A M.

In: Equine Veterinary Journal, Vol. 37, No. 2, 2005, p. 161-165.

Research output: Contribution to journalArticle

@article{29ddb4dd93e444a2a5dc816dc2ddc75a,
title = "Deep digital flexor tendon force and digital mechanics in normal ponies and ponies with rotation of the distal phalanx as a sequel to laminitis",
abstract = "Reasons for performing study: Previous studies have implicated tension in the deep digital flexor tendon (DDFT) in the rotation of the distal phalanx (DP) after the breakdown of the dorsal laminae caused by laminitis. Howeveer, once the DP has rotated, the DDFT should become shorter, reducing the force it exerts on the DP. Objective: To compare DDFT force and ground reaction forces (GRFs) in normal ponies and ponies with rotation of the DP as a sequel to laminitis. Methods: Six normal ponies (Group 1) and 6 sound ponies with 6-13degrees of rotation of the DP in relation to the dorsal hoof wall (Group 2) were assessed at trot using forceplate and motion analysis. The force in the DDFT was calculated by assuming that the extending moment at the distal interphalangeal (DIP) joint resulting from the GRF was equal to the flexing moment created by the force in the DDFT during the stance phase (inverse dynamics). Results: In early stance, the peak DDFT force (mean +/- s.d.) in the normal ponies was 1.92 +/- 1.63 N/kg. However, in Group 2, the point of zero moment was palmar to the centre of rotation of the DIP joint for the first 40{\%} of stance and hence DDFT force was zero. Force in the DDFT reached a peak of 10.00 +/- 3.56 N/kg at 60.7 +/- 5.6{\%} of stance in Group 1 and 6.41 +/- 1.37 N/kg at 79.2 +/- 9.6{\%} of stance in Group 2. Conclusions: DDFT force in Group 2 laminitic ponies was much reduced until late stance, when it neared normal values. Potential relevance: Further studies of ponies with rotation of the DP as a sequel to laminitis should assist farriery aimed at reducing the force in the DDFT through the breakover phase of stance to protect damaged dorsal laminae.",
author = "McGuigan, {M P} and Walsh, {T C} and Pardoe, {C H} and Day, {P S} and Wilson, {A M}",
note = "ID number: ISI:000227468600012",
year = "2005",
language = "English",
volume = "37",
pages = "161--165",
journal = "Equine Veterinary Journal",
issn = "0425-1644",
publisher = "British Equine Veterinary Association",
number = "2",

}

TY - JOUR

T1 - Deep digital flexor tendon force and digital mechanics in normal ponies and ponies with rotation of the distal phalanx as a sequel to laminitis

AU - McGuigan, M P

AU - Walsh, T C

AU - Pardoe, C H

AU - Day, P S

AU - Wilson, A M

N1 - ID number: ISI:000227468600012

PY - 2005

Y1 - 2005

N2 - Reasons for performing study: Previous studies have implicated tension in the deep digital flexor tendon (DDFT) in the rotation of the distal phalanx (DP) after the breakdown of the dorsal laminae caused by laminitis. Howeveer, once the DP has rotated, the DDFT should become shorter, reducing the force it exerts on the DP. Objective: To compare DDFT force and ground reaction forces (GRFs) in normal ponies and ponies with rotation of the DP as a sequel to laminitis. Methods: Six normal ponies (Group 1) and 6 sound ponies with 6-13degrees of rotation of the DP in relation to the dorsal hoof wall (Group 2) were assessed at trot using forceplate and motion analysis. The force in the DDFT was calculated by assuming that the extending moment at the distal interphalangeal (DIP) joint resulting from the GRF was equal to the flexing moment created by the force in the DDFT during the stance phase (inverse dynamics). Results: In early stance, the peak DDFT force (mean +/- s.d.) in the normal ponies was 1.92 +/- 1.63 N/kg. However, in Group 2, the point of zero moment was palmar to the centre of rotation of the DIP joint for the first 40% of stance and hence DDFT force was zero. Force in the DDFT reached a peak of 10.00 +/- 3.56 N/kg at 60.7 +/- 5.6% of stance in Group 1 and 6.41 +/- 1.37 N/kg at 79.2 +/- 9.6% of stance in Group 2. Conclusions: DDFT force in Group 2 laminitic ponies was much reduced until late stance, when it neared normal values. Potential relevance: Further studies of ponies with rotation of the DP as a sequel to laminitis should assist farriery aimed at reducing the force in the DDFT through the breakover phase of stance to protect damaged dorsal laminae.

AB - Reasons for performing study: Previous studies have implicated tension in the deep digital flexor tendon (DDFT) in the rotation of the distal phalanx (DP) after the breakdown of the dorsal laminae caused by laminitis. Howeveer, once the DP has rotated, the DDFT should become shorter, reducing the force it exerts on the DP. Objective: To compare DDFT force and ground reaction forces (GRFs) in normal ponies and ponies with rotation of the DP as a sequel to laminitis. Methods: Six normal ponies (Group 1) and 6 sound ponies with 6-13degrees of rotation of the DP in relation to the dorsal hoof wall (Group 2) were assessed at trot using forceplate and motion analysis. The force in the DDFT was calculated by assuming that the extending moment at the distal interphalangeal (DIP) joint resulting from the GRF was equal to the flexing moment created by the force in the DDFT during the stance phase (inverse dynamics). Results: In early stance, the peak DDFT force (mean +/- s.d.) in the normal ponies was 1.92 +/- 1.63 N/kg. However, in Group 2, the point of zero moment was palmar to the centre of rotation of the DIP joint for the first 40% of stance and hence DDFT force was zero. Force in the DDFT reached a peak of 10.00 +/- 3.56 N/kg at 60.7 +/- 5.6% of stance in Group 1 and 6.41 +/- 1.37 N/kg at 79.2 +/- 9.6% of stance in Group 2. Conclusions: DDFT force in Group 2 laminitic ponies was much reduced until late stance, when it neared normal values. Potential relevance: Further studies of ponies with rotation of the DP as a sequel to laminitis should assist farriery aimed at reducing the force in the DDFT through the breakover phase of stance to protect damaged dorsal laminae.

M3 - Article

VL - 37

SP - 161

EP - 165

JO - Equine Veterinary Journal

JF - Equine Veterinary Journal

SN - 0425-1644

IS - 2

ER -