Improving the understanding on the use of the One Leg Sit to Stand when assessing individuals with patellofemoral pain: an analysis of the association of knee extensor strength and levels of pain with functional performance

• Grant number: 22/16711-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: April 01, 2023
• End date: December 31, 2023
• Field of knowledge: Health Sciences - Physiotherapy and Occupational Therapy
• Principal Investigator: Fábio Mícolis de Azevedo
• Grantee: Lucas Leonardo Marcelino Joia
• Host Institution: Faculdade de Ciências e Tecnologia (FCT). Universidade Estadual Paulista (UNESP). Campus de Presidente Prudente. Presidente Prudente , SP, Brazil

Abstract

Patellofemoral pain (PFP) is a common musculoskeletal disorder that affects 23% of thegeneral population and is characterized by diffuse anterior knee pain, exacerbated byfunctional/daily activities. Impairments in the knee extensor strength are commonlyreported in individuals with PFP. Such impairments are even related to their higher levelsof pain and lower function. The apparent importance of knee extensor strength in thispopulation makes its assessment a fundamental component of a clinician's physicalexamination. Such an assessment can be performed through isokinetic or portabledynamometers, though they are costly and may not be accessible to all clinical settings.On the other hand, clinical tests provide low-cost objective measures with easyaccessibility and applicability in a clinical setting. Recent studies have reported anegative relationship between the functional performance during clinical tests, such as theOne Leg Sit To Stand (OLSTS), with the maximal strength of the knee extensor musclesin individuals with knee osteoarthritis and anterior cruciate ligament reconstruction;which makes this test a good option to traditional measures of strength in clinicalsettings. Similar findings may be reported for those with PFP; however, such aninvestigation is warranted. It may be also needed to better understand the effect of thelevel of pain on the functional performance of individuals with PFP during the OLSTS astheir pain variability and exacerbation during tasks simulated by clinical tests. Such aninvestigation may help guiding clinicians on the interpretation of the OLSTS when thisclinical test is used to assess knee strength as an outcome during the treatment ofindividuals with PFP. A study comparing the functional performance of individuals withPFP during the OLSTS before and after symptoms exacerbation may be warranted tobetter understand this issue. Therefore, the aims of this project were twofold: (I) toinvestigate the relationship between the functional performance during the OLSTS withknee extensor strength as assessed by portable dynamometry; and (II) to compare thefunctional performance during the OLSTS in individuals with and without PFP before andafter a patellofemoral joint loading protocol. Males and females with and without PFPaged 18 to 35 years old will be recruited. Maximal isometric knee extensor torque will beassessed using a portable dynamometer and the average three trials normalized byparticipant's body mass will be obtained for analysis. The functional performance duringthe OLSTS will be assessed by performing as many repetitions as possible in a single trialuntil failure and the number of repetitions performed before and after a patellofemoraljoint loading protocol will be obtained for analysis. Pearson or Spearman correlationscoefficients will be used to determine the relationship between maximal knee extensortorque and the functional performance during the OLSTS in individuals with PFP. A 2×2analysis of variance (ANOVA) will be used to compare the functional performance duringthe OLSTS in individuals with and without PFP before and after the loading protocol.