Don't Assume the Control Group Is Normal

People with Asymptomatic Tendon Pathology Have Higher Pressure Pain Thresholds

Ebonie K Rio, Richard F Ellis, Jono M Henry, Victoria R Falconer, Zoltan S Kiss, Michael A Girdwood, Jill L Cook, Jamie E Gaida

Research output: Contribution to journalArticle

Abstract

Objective: Pain pressure thresholds (PPT) are used to study peripheral and central pain processing. In the tendon, pathological changes may exist without pain. This pilot study aimed to compare PPT between individuals with normal tendons and asymptomatic tendon pathology, and between individuals with and without a history of tendon pain.

Methods: The patellar, Achilles, and supraspinatus tendons of 128 asymptomatic participants were examined with ultrasound. Global PPT average was determined using a digital algometer at the patellar tendon, quadriceps muscle, L3 spinous process, and deltoid muscle insertion. Participants were separated into three groups: (1) healthy control group (no pathology, no history of pain), (2) tendon pathology at any site without a history of pain, (3) history of tendon pain anywhere.

Results: There were 92 controls, seven with asymptomatic pathology and 29 with a history of tendon pain. Asymptomatic tendon pathology at any site (without a history of pain) was associated with globally increased PPTs compared with controls (P < 0.001, pathology N = 7, N = 92 controls). Matched pair analysis remained significant (P < 0.004). A history of tendon pain was associated with globally increased PPTs compared with the control group (P = 0.026). Matched pair analysis was not significant (P = 0.122).

Conclusions: Asymptomatic tendon pathology is associated with higher PPTs. These findings point toward central nervous system adaptations but in a novel way-central desensitization. This challenges the validity of conclusions drawn from PPT studies that do not verify normal structure in the control group; artificial inflation of control group data may incorrectly indicate decreased PPTs in the comparison group.

Original languageEnglish
Pages (from-to)2267-2273
Number of pages7
JournalPain Medicine (United States)
Volume19
Issue number11
Early online date22 Jun 2018
DOIs
Publication statusPublished - Nov 2018

Fingerprint

Pain Threshold
Tendons
Pathology
Pressure
Control Groups
Pain
Matched-Pair Analysis
Deltoid Muscle
Patellar Ligament
Achilles Tendon
Rotator Cuff
Quadriceps Muscle
Economic Inflation
Central Nervous System

Cite this

Rio, Ebonie K ; Ellis, Richard F ; Henry, Jono M ; Falconer, Victoria R ; Kiss, Zoltan S ; Girdwood, Michael A ; Cook, Jill L ; Gaida, Jamie E. / Don't Assume the Control Group Is Normal : People with Asymptomatic Tendon Pathology Have Higher Pressure Pain Thresholds. In: Pain Medicine (United States). 2018 ; Vol. 19, No. 11. pp. 2267-2273.
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title = "Don't Assume the Control Group Is Normal: People with Asymptomatic Tendon Pathology Have Higher Pressure Pain Thresholds",
abstract = "Objective: Pain pressure thresholds (PPT) are used to study peripheral and central pain processing. In the tendon, pathological changes may exist without pain. This pilot study aimed to compare PPT between individuals with normal tendons and asymptomatic tendon pathology, and between individuals with and without a history of tendon pain.Methods: The patellar, Achilles, and supraspinatus tendons of 128 asymptomatic participants were examined with ultrasound. Global PPT average was determined using a digital algometer at the patellar tendon, quadriceps muscle, L3 spinous process, and deltoid muscle insertion. Participants were separated into three groups: (1) healthy control group (no pathology, no history of pain), (2) tendon pathology at any site without a history of pain, (3) history of tendon pain anywhere.Results: There were 92 controls, seven with asymptomatic pathology and 29 with a history of tendon pain. Asymptomatic tendon pathology at any site (without a history of pain) was associated with globally increased PPTs compared with controls (P < 0.001, pathology N = 7, N = 92 controls). Matched pair analysis remained significant (P < 0.004). A history of tendon pain was associated with globally increased PPTs compared with the control group (P = 0.026). Matched pair analysis was not significant (P = 0.122).Conclusions: Asymptomatic tendon pathology is associated with higher PPTs. These findings point toward central nervous system adaptations but in a novel way-central desensitization. This challenges the validity of conclusions drawn from PPT studies that do not verify normal structure in the control group; artificial inflation of control group data may incorrectly indicate decreased PPTs in the comparison group.",
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Don't Assume the Control Group Is Normal : People with Asymptomatic Tendon Pathology Have Higher Pressure Pain Thresholds. / Rio, Ebonie K; Ellis, Richard F; Henry, Jono M; Falconer, Victoria R; Kiss, Zoltan S; Girdwood, Michael A; Cook, Jill L; Gaida, Jamie E.

In: Pain Medicine (United States), Vol. 19, No. 11, 11.2018, p. 2267-2273.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Don't Assume the Control Group Is Normal

T2 - People with Asymptomatic Tendon Pathology Have Higher Pressure Pain Thresholds

AU - Rio, Ebonie K

AU - Ellis, Richard F

AU - Henry, Jono M

AU - Falconer, Victoria R

AU - Kiss, Zoltan S

AU - Girdwood, Michael A

AU - Cook, Jill L

AU - Gaida, Jamie E

PY - 2018/11

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N2 - Objective: Pain pressure thresholds (PPT) are used to study peripheral and central pain processing. In the tendon, pathological changes may exist without pain. This pilot study aimed to compare PPT between individuals with normal tendons and asymptomatic tendon pathology, and between individuals with and without a history of tendon pain.Methods: The patellar, Achilles, and supraspinatus tendons of 128 asymptomatic participants were examined with ultrasound. Global PPT average was determined using a digital algometer at the patellar tendon, quadriceps muscle, L3 spinous process, and deltoid muscle insertion. Participants were separated into three groups: (1) healthy control group (no pathology, no history of pain), (2) tendon pathology at any site without a history of pain, (3) history of tendon pain anywhere.Results: There were 92 controls, seven with asymptomatic pathology and 29 with a history of tendon pain. Asymptomatic tendon pathology at any site (without a history of pain) was associated with globally increased PPTs compared with controls (P < 0.001, pathology N = 7, N = 92 controls). Matched pair analysis remained significant (P < 0.004). A history of tendon pain was associated with globally increased PPTs compared with the control group (P = 0.026). Matched pair analysis was not significant (P = 0.122).Conclusions: Asymptomatic tendon pathology is associated with higher PPTs. These findings point toward central nervous system adaptations but in a novel way-central desensitization. This challenges the validity of conclusions drawn from PPT studies that do not verify normal structure in the control group; artificial inflation of control group data may incorrectly indicate decreased PPTs in the comparison group.

AB - Objective: Pain pressure thresholds (PPT) are used to study peripheral and central pain processing. In the tendon, pathological changes may exist without pain. This pilot study aimed to compare PPT between individuals with normal tendons and asymptomatic tendon pathology, and between individuals with and without a history of tendon pain.Methods: The patellar, Achilles, and supraspinatus tendons of 128 asymptomatic participants were examined with ultrasound. Global PPT average was determined using a digital algometer at the patellar tendon, quadriceps muscle, L3 spinous process, and deltoid muscle insertion. Participants were separated into three groups: (1) healthy control group (no pathology, no history of pain), (2) tendon pathology at any site without a history of pain, (3) history of tendon pain anywhere.Results: There were 92 controls, seven with asymptomatic pathology and 29 with a history of tendon pain. Asymptomatic tendon pathology at any site (without a history of pain) was associated with globally increased PPTs compared with controls (P < 0.001, pathology N = 7, N = 92 controls). Matched pair analysis remained significant (P < 0.004). A history of tendon pain was associated with globally increased PPTs compared with the control group (P = 0.026). Matched pair analysis was not significant (P = 0.122).Conclusions: Asymptomatic tendon pathology is associated with higher PPTs. These findings point toward central nervous system adaptations but in a novel way-central desensitization. This challenges the validity of conclusions drawn from PPT studies that do not verify normal structure in the control group; artificial inflation of control group data may incorrectly indicate decreased PPTs in the comparison group.

KW - Musculoskeletal

KW - Ultrasound

KW - central sensitisation

KW - Pressure pain threshold

KW - asymptomatic pathology

KW - tendon

U2 - 10.1093/pm/pny117

DO - 10.1093/pm/pny117

M3 - Article

VL - 19

SP - 2267

EP - 2273

JO - Pain Medicine (United States)

JF - Pain Medicine (United States)

SN - 1526-2375

IS - 11

ER -