The Effect of a Treatment Protocol Focused on Neuromuscular Control Exercises on Pain and Function in a Subgroup of Individuals With Patellofemoral Pain

This study proposes a treatment protocol focused on neuromuscular control in a subgroup of individuals with PFP and may provide important information on the effectiveness of different treatment approaches for patellofemoral pain. It would be interesting to establish objectives according to clinical findings, and thus identify the best treatment protocols for specific subgroups of PFP. For a long time, the focus of rehabilitation has been on decreasing knee pain and strengthening the muscles around the knee to improve knee joint function (Piva et al., 2009) in a generalized way for all individuals with PFP. However, with recent information in the literature on the presence of subgroups, a study with a treatment protocol focused on neuromuscular control directed at a subgroup has not yet been carried out, which is the objective of this work. Thus, the hypothesis to be tested is that individuals from a PFP subgroup will present better results with neuromuscular control exercises than those performing muscle strengthening in the same treatment period.

The aim of this study is to compare the effects of two 6-week treatment protocols a) based on neuromuscular control exercises, and b) muscle strengthening on outcome measures of pain, function and biomechanical variables in a subgroup of individuals with PFP during stair ascent and descent.

-Detailed Description This study will be carried out at the Porto Biomechanics Laboratory (LABIOMEP) and at the gym of the Faculty of Sports (FADEUP) of University of Porto. The recruitment of volunteers for this project will take place in the city of Porto, Portugal. Participants will be invited to participate in the study if they self-report anterior knee pain exacerbated during a squatting test and/or during any sporting practice. Folders with all the information necessary for recruitment will be distributed among the academic and general community, recreational athletes during sporting events and on social media.

Sample calculation A sample size calculation was performed based on the minimal detectable change on the Visual Analog Pain Scale (VAS). Data from a previous study indicate that the mean VAS score in patients with PFP was 4.3 ± 1 cm (Crossley et al. 2004), with 30% of the maximum score of the VAS-pain considered to be the detectable change. The sample size for each group to achieve a 90% power at the 0.05 level of significance was determined to be 8 patients. Thus, the sample will consist of 20 volunteers (ten per group) of both sexes diagnosed with PFP.

Inclusion criteria Men and women aged 18-40 years old that can give informed written consent. Clinical diagnosis of unilateral or bilateral PFP longer than 3 months (exemplified in the following sections).