Efeitos do volume de treino resistido na mudança da dor e função em pacientes com dor patelofemoral: uma revisão sistemática com metanálise

Abstract

Patellofemoral Pain (PFP) is defined as retro or peripatellar pain provoked by activities that increase the load on the patellofemoral joint. According to clinical guidelines for this condition, the gold standard management is conducted through exercise­based physiotherapy, focusing on knee and hip joints. Thus, Resistance Training (RT) is the primary modality for clinical improvement in these patients, showing benefits in pain and function outcomes in the short, medium, and long term. Despite numerous studies investigating this condition, there are still gaps in the intervention context. One of them is attempting to focus on a specific target musculature for clinical improvement or not equalizing the total training volume in interventions, leading to uncertainty about the real treatment effect, as one group usually undergoes more stimuli than the other. Against this background, the aim of this study was to investigate whether the volume of resistance training interferes with the improvement of pain and function in individuals with Patellofemoral Pain. This study is a Systematic Review of Randomized Controlled Trials and is prospectively registered in the International Prospective Register of Systematic Reviews (PROSPERO) with the identification number CRD42021274218. The systematic review followed the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta­Analyses (PRISMA) statement and assessed the quality of evidence using GRADE. It comprised Randomized Controlled Trials summarized in the literature, without restrictions on language and publication date, through the respective databases: Pubmed, Pedro, Central, Embase, and Cinahl. The inclusion criteria were studies with men and women aged between 15 and 45 years who had anterior knee pain (retro or peripatellar) with a clinical diagnosis of patellofemoral pain, undergoing resistance training as intervention. The exclusion criteria were studies where participants had lower back or hip pain, a history of spine surgery, knee trauma, lower limb fractures, lower limb surgery, and associated knee injuries (osteoarthritis, meniscal injury, tendon injury, patellar dislocation, ligament injury). Thirty studies involving 1,670 participants were included in the review. Comparisons were made between non­equalized volumes (high volume vs. low volume) and equalized volumes (experimental vs. control/ knee vs. hip). In the equalized volumes, thirteen studies compared high­volume training versus low­volume training for the pain outcome (MD= ­1.04; 95% CI ­1.78 to ­0.31, p= 0.005; n= 646), and seven studies made the same comparison for the function outcome (SMD= 0.35; 95% CI ­0.03 to 0.73, p= 0.07; n= 601) immediately after the intervention period. Beyond the intervention period for both primary outcomes of pain and function, a total of five studies were considered (MD= ­1.56; 95% CI ­2.98 to ­0.13, p= 0.03; n= 194; SMD= 0.99; 95% CI 0.14 to 1.84, p= 0.02; n= 194), respectively. Other meta­analyses of pain and function were also conducted for equalized volumes both immediately after the intervention period and beyond. Therefore, it can be said that a higher volume of training in an RT intervention has a more significant impact on reducing pain and increasing function when compared to a lower volume of training. Moreover, there is no difference in the strengthening of different muscle groups to improve pain and function in people with PFP when the training volume is equalized between the groups.