Strength and Pain Threshold Handheld Dynamometry Test Reliability in Patellofemoral Pain

Abstract

Patellofemoral pain syndrome (PFPS), characterized by peri- and retropatellar pain, is a common disorder in young, active people. The etiology is unclear; however, quadriceps strength seems to be a contributing factor, and sensitization might play a role. The study purpose is determining the inter-rater reliability of handheld dynamometry to test both quadriceps strength and pressure pain threshold (PPT), a measure for sensitization, in patients with PFPS. This cross-sectional case-control study comprises 3 quadriceps strength and one PPT measurements performed by 2 independent investigators in 22 PFPS patients and 16 matched controls. Inter-rater reliability was analyzed using intraclass correlation coefficients (ICC) and Bland-Altman plots. Inter-rater reliability of quadriceps strength testing was fair to good in PFPS patients (ICC=0.72) and controls (ICC=0.63). Bland-Altman plots showed an increased difference between assessors when average quadriceps strength values exceeded 250 N. Inter-rater reliability of PPT was excellent in patients (ICC=0.79) and fair to good in controls (ICC=0.52). Handheld dynamometry seems to be a reliable method to test both quadriceps strength and PPT in PFPS patients. Inter-rater reliability was higher in PFPS patients compared to control subjects. With regard to quadriceps testing, a higher variance between assessors occurs when quadriceps strength increases.

Psychological and pain profiles in persons with patellofemoral pain as the primary symptom

“…Level 1 evidence outlined in systematic reviews demonstrates that individuals with knee osteoarthritis have hyperalgesia, increased TSP and impaired CPM (De Oliveira Silva, Rathleff, Petersen, Azevedo, & Barton, 2019;Fingleton, Smart, Moloney, Fullen, & Doody, 2015;Lluch, Torres, Nijs, & Oosterwijck, 2014;Suokas et al, 2012). When assessed in PFP, widespread hyperalgesia is commonly reported (Noehren et al, 2015;Pazzinatto et al, 2016;Rathleff, Roos, Olesen, Rasmussen, & Arendt-Nielsen, 2013;van der Heijden, Rijndertse, Bierma-Zeinstra, & Middelkoop, 2017). The evidence for other pain phenomena remains is less conclusive, with both TSP (Holden et al, 2018;Rathleff, Petersen, Arendt-Nielsen, Thorborg, & Graven-Nielsen, 2015) and CPM (Holden et al, 2018;Rathleff et al, 2015Rathleff et al, , 2017 demonstrating mixed results.…”

Exploring the Pain in Patellofemoral Pain: A Systematic Review and Meta-Analysis Examining Signs of Central Sensitization

“…Of the included studies, five studies used pressure algometry, 27,28,37-39 two studies used cuff algometry 36,40 and two studies used a handheld dynamometer method. 41,42 Non-significant group differences were only observed in one study, and it may be worth noting that the mean age was older than most studies (28.5 years). Based on our subgroup analyses, both female-only and mixed-sex studies maintained statistical heterogeneity.…”

“…Strong evidence27,28,[36][37][38][39][40][41][42] (n= 983) from 6 high-and 5 moderate-quality studies supports a large significant SMD [-0.91 (-1.22, -0.60); Figure 2] in local (knee) PPTs between individuals with PFP compared to healthy, pain-free controls. A post hoc subgroup analysis was conducted to explore the effect of sex (female-only studies vs. mixed-sex studies) on local PPTs.…”

Characteristics and Outcome of Patellofemoral Pain in Adolescents: Do They Differ From Adults?

“…6 Strength of the quadriceps and hip musculature for abduction and external rotation was measured using a handheld dynamometer (MicroFET2; Fabrication Enterprises Inc, Elmsford, NY), which is a reliable method to measure strength in individuals with PFP. 18 Strength measurements were repeated 3 times, and the mean of the highest 2 values was used for analyses (Newton meters per square centimeter). All strength data were subsequently normalized to body weight (Newtons per kilogram).…”