Overweight and obesity in young adults with patellofemoral pain: Impact on functional capacity and strength

Body fat and skeletal muscle mass predict knee strength and pain in young women with patellofemoral pain

INTRODUCTION

Patellofemoral pain (PFP) is a chronic dysfunction, with a high prevalence in young women and characterized by complaints of recurrent pain and a poor long-term prognosis. With a multifactorial characteristic, recent studies point to a possible association between body composition and PFP outcomes, however the results are still unclear.

OBJECTIVE

to investigate whether there is an association between BMI, skeletal muscle mass and body fat with physical function, knee strength and pain in women with PFP.

METHODS

Twenty-four women, aged between 18 and 35 years, diagnosed with PFP, were recruited for this study. Body fat and skeletal muscle mass were quantified using tetrapolar bioimpedance systems. Pressure hyperalgesia was evaluated using an algometer. Maximal strength during concentric contraction of the knee extensors was measured with an isokinetic dynamometer. Objective function assessment included the single-leg hop test, step-down test, single-legged chair stand test, and side hop. The Pearson correlation test was utilized, with a significance level set at p < 0.05.

RESULTS

Significant negative correlations were found between BMI and body fat with knee extensor torque. There was a positive correlation between skeletal muscle mass and knee extensor torque. For objective function, there was a negative correlation between body fat and performance in the side hope, single leg hop test and stair climbing test. Local pressure hyperalgesia was associated with skeletal muscle mass and body fat.

CONCLUSION

Body composition should be factored into the evaluation and management of young women with PFP, as it correlates with deficiencies in functional performance, muscle torque, and pain.

Hip Muscle Strength and Fear of Movement are Associated with Self-Reported Function in Women with Patellofemoral Pain

OBJECTIVES

We aimed to investigate the relationship between self-reported lower extremity function, fear of movement, and quadriceps, hamstring, and hip stabilizer muscle strength in women with patellofemoral pain.

METHODS

Fifty-four women (age: 32.59±7.00) were included in the study. We assessed self-reported function with the Lower Extremity Functional Scale and fear of movement with the Tampa Scale for kinesiophobia. The strength of the quadriceps, hamstring, and hip stabilizer muscles was determined with a hand-held dynamometer. Relationships between variables were examined using Pearson correlation analysis and binary logistic regression analysis.

RESULTS

Self-reported function showed a moderate positive correlation with hip stabilizer muscle strength (r=0.408, p=0.002) and negative correlation with fear of movement (r=-0.500, p<0.01).

CONCLUSION

The results of this study suggest that fear of movement and hip stabilizer muscle strength are factors associated with self-reported lower extremity function in women with patellofemoral pain.

People With Patellofemoral Pain Have Bilateral Deficits in Physical Performance Regardless of Pain Laterality

CONTEXT

People with patellofemoral pain (PFP) may have lower performance during the forward step-down and single-leg hop with their painful (unilateral complaints) or most painful (bilateral complaints) limb when compared with pain-free controls. However, no authors have investigated the appropriateness of using the pain-free or less painful limb as a reference standard in clinical practice or whether deficits might be present depending on the laterality of pain.

OBJECTIVE

To compare performance scores and proportion of side-to-side limb symmetry during the forward step-down and single-leg hop tests among people with unilateral and bilateral PFP and pain-free controls.

DESIGN

Cross-sectional study.

SETTING

Laboratory.

PATIENTS OR OTHER PARTICIPANTS

Fifty-two young adults (18-35 years old) with unilateral PFP, 72 with bilateral PFP, and 76 controls.

MAIN OUTCOME MEASURE(S)

Group × limb interactions on performance during the step-down (repetitions) and single-leg hop (distance [cm] normalized by the limb length) tests were investigated using a repeated-measures analysis of covariance controlling for sex. Pairwise comparisons were interpreted using effect sizes. A χ2 test was used to compare the proportion of symmetry/asymmetry (cutoff point of ≥90% for symmetry indices) across groups and tests.

RESULTS

Main effects for groups (small to medium effects) but not limbs indicated lower performance of both limbs of individuals with unilateral and bilateral PFP than controls during forward step-down and single-leg hop tests. No significant differences for the proportion of symmetry/asymmetry were identified across groups (P ≥.05), which further suggests an impaired physical performance of the contralateral limb.

CONCLUSIONS

Our results indicate bilateral deficits in the physical performance of people with unilateral and bilateral PFP when compared with pain-free controls during the forward step-down and single-leg hop tests. Limb symmetry indices greater than 90% should be interpreted with caution, as they may overstate physical performance by not assuming bilateral deficits.

Isokinetic Knee Strengthening Impact on Physical and Functional Performance, Pain Tolerance, and Quality of Life in Overweight/Obese Women with Patellofemoral Pain Syndrome

Background/Objectives: Patellofemoral syndrome is a common osteoarticular condition that affects many individuals. Various treatment options are available, with a significant emphasis on targeted muscle-strengthening exercises. The purpose of this study was to investigate the effect of isokinetic muscle strengthening on muscle strength, joint range of motion, quality of life, physical performance, and pain tolerance in overweight/obese women with patellofemoral syndrome. Methods: Twenty-four overweight or obese women with patellofemoral syndrome participated in the study during September and October 2023 in a private medical facility for physical medicine and functional rehabilitation. They were randomly assigned to one of two groups for six weeks of isokinetic muscle strengthening. The first group (ISO.G) followed a rehabilitation program combined with isokinetic muscle strengthening. A second group (PCM.G) followed a rehabilitation program that includes an isokinetic protocol in passive compensation movement. The extensors' peak torque was measured before and after training. Results: The flexors' peak torque, stair climbing test, 10 m walk, chair lift, monopodal support, goniometric knee flexion test, heel-buttock distance measurement, pain, and quality of life scores improved significantly in both groups. The ISO.G, on the other hand, benefited from a significant increase in quadriceps muscle strength revealed by the extensors' peak torque. Conclusions: For the treatment of patellofemoral syndrome, isokinetic muscle strengthening in concentric mode appears to have a significant advantage over the classic rehabilitation program with isokinetic passive compensation, particularly in muscle strength gain, in addition to the improvement of joint range of motion, quality of life, physical performance, and pain tolerance. Isokinetic training may be recommended as a beneficial approach for the rehabilitative treatment of patellofemoral pain syndrome in overweight/obese women.

The Influence of Psychological Factors on Physical Activity in Individuals With Patellofemoral Pain

CONTEXT

Patellofemoral pain (PFP) is a prevalent chronic condition characterized by retropatellar or peripatellar pain exacerbated by various knee flexion-based activities. Previous research has highlighted the impact of psychological constructs on pain and function in chronic musculoskeletal pain conditions, yet their influence on physical activity in PFP cohorts remains unexplored. We aimed to evaluate whether pain self-efficacy and pain catastrophizing predict variations in steps per day and moderate to vigorous physical activity (MVPA) among individuals with PFP.

DESIGN

Cross-sectional observational study.

METHODS

Thirty-nine participants (11 males) with PFP were included. Dependent variables were steps per day and minutes of MVPA. Independent variables were pain self-efficacy and pain catastrophizing, measured by the pain self-efficacy questionnaire and the pain catastrophizing scale. Participants were given an ActiGraph wGT3X-BT for 7 days to assess physical activity. Correlations were assessed between psychological measures and physical activity, and a simple linear regression was performed on psychological variables that correlated with physical activity. Alpha was set a priori at P < .05.

RESULTS

Pain self-efficacy scores displayed a moderate association with steps per day (rho = .45, P = .004) and a weak association with MVPA (rho = .38, P = .014). Pain catastrophizing scores exhibited no significant associations with physical activity (P < .05). Regression models affirmed pain self-efficacy scores as significant predictors of both steps per day (F1,37 = 10.30, P = .002) and MVPA (F1,37 = 8.98, P = .004).

CONCLUSIONS

Psychological measures continue to demonstrate value to clinicians treating PFP. Pain self-efficacy scores were moderately associated with steps per day and weakly associated with MVPA, explaining nearly a fifth of the variation in physical activity. Clinicians should prioritize the assessment of pain self-efficacy when treating individuals with PFP, potentially employing psychological interventions to improve physical activity in the PFP population.

Exploring overweight and obesity beyond body mass index: A body composition analysis in people with and without patellofemoral pain

BACKGROUND

We compared body mass index (BMI), body fat, and skeletal muscle mass between (1) a mixed-sex nonathletic cohort of people with patellofemoral pain (PFP) and pain-free people, and (2) a nonathletic cohort of people with PFP and pain-free people subgrouped by sex (i.e., men and women with PFP vs. pain-free men and women).

METHODS

This cross-sectional study included 114 people with PFP (71 women, 43 men) and 54 pain-free controls (32 women, 22 men). All participants attended a single testing session to assess body composition measures, which included BMI, percentage of body fat (%BFBioimpedance), and skeletal muscle mass (both assessed by bioelectrical impedance analysis), and percentage of body fat (%BFSkinfold) (assessed by skinfold caliper analysis). A one-way univariate analysis of covariance (age and physical activity levels as covariates) was used to compare body composition measures between groups (i.e., PFP vs. pain-free group; women with PFP vs. pain-free women; men with PFP vs. pain-free men).

RESULTS

Women with PFP presented significantly higher BMI, %BFBioimpedance, and %BFSkinfold, and lower skeletal muscle mass compared to pain-free women (p ≤ 0.04; effect size : ‒0.47 to 0.85). Men with PFP and men and women combined had no differences in BMI, %BFBioimpedance, %BFSkinfold, and skeletal muscle mass compared to their respective pain-free groups (p > 0.05).

CONCLUSION

Our findings indicate that BMI and body composition measures should be considered as part of the evaluation and management of people with PFP, especially in women, who have demonstrated higher BMI and body fat and lower skeletal muscle mass compared to pain-free controls. Future studies should not assess body composition measures in a mixed-sex population without distinguishing men participants from women participants.

Trajectory of knee health in runners with and without heightened osteoarthritis risk: the TRAIL prospective cohort study protocol

INTRODUCTION

Running is one of the most popular recreational activities worldwide, due to its low cost and accessibility. However, little is known about the impact of running on knee joint health in runners with and without a history of knee surgery. The primary aim of this longitudinal cohort study is to compare knee joint structural features on MRI and knee symptoms at baseline and 4-year follow-up in runners with and without a history of knee surgery. Secondary aims are to explore the relationships between training load exposures (volume and/or intensity) and changes in knee joint structure and symptoms over 4 years; explore the relationship between baseline running biomechanics, and changes in knee joint structure and symptoms over 4 years. In addition, we will explore whether additional variables confound, modify or mediate these associations, including sex, baseline lower-limb functional performance, knee muscle strength, psychological and sociodemographic factors.

METHODS AND ANALYSIS

A convenience sample of at least 200 runners (sex/gender balanced) with (n=100) and without (n=100) a history of knee surgery will be recruited. Primary outcomes will be knee joint health (MRI) and knee symptoms (baseline; 4 years). Exposure variables for secondary outcomes include training load exposure, obtained daily throughout the study from wearable devices and three-dimensional running biomechanics (baseline). Additional variables include lower limb functional performance, knee extensor and flexor muscle strength, biomarkers, psychological and sociodemographic factors (baseline). Knowledge and beliefs about osteoarthritis will be obtained through predefined questions and semi-structured interviews with a subset of participants. Multivariable logistic and linear regression models, adjusting for potential confounding factors, will explore changes in knee joint structural features and symptoms, and the influence of potential modifiers and mediators.

ETHICS AND DISSEMINATION

Approved by the La Trobe University Ethics Committee (HEC-19524). Findings will be disseminated to stakeholders, peer-review journals and conferences.

Body fat and skeletal muscle mass, but not body mass index, are associated with pressure hyperalgesia in young adults with patellofemoral pain

BACKGROUND

Young adults with patellofemoral pain (PFP) have a high prevalence of being overweight or obese, which is associated with impaired lower limb function and muscle weakness. However, the impact of being overweight or obese on pain sensitivity has not been explored.

OBJECTIVES

We investigated the association between body fat, skeletal muscle mass, and body mass index (BMI) with pressure hyperalgesia and self-reported pain in young adults with PFP.

METHODS

114 adults with PFP (24 ± 5 years old, 62% women) were recruited. Demographics and self-reported pain (current and worst knee pain intensity in the previous month - 0-100 mm visual analog scale) were recorded. Body fat and skeletal muscle mass were measured using bioelectrical impedance. Pressure hyperalgesia was measured using a handheld algometer (pressure pain threshold) at three sites: center of patella of the painful knee, ipsilateral tibialis anterior, and contralateral upper limb. The association between body fat, skeletal muscle mass, and BMI with pressure hyperalgesia and self-reported pain were investigated using partial correlations and hierarchical regression models (adjusted for sex, bilateral pain, and symptoms duration).

RESULTS

Higher body fat and lower skeletal muscle mass were associated with local, spread, and widespread pressure hyperalgesia (ΔR²=0.09 to 0.17, p ≤ 0.001; ΔR²=0.14 to 0.26, p<0.001, respectively), and higher current self-reported pain (ΔR²=0.10, p<0.001; ΔR²=0.06, p = 0.007, respectively). Higher BMI was associated with higher current self-reported pain (ΔR²=0.10, p = 0.001), but not with any measures of pressure hyperalgesia (p>0.05).

CONCLUSION

Higher body fat and lower skeletal muscle mass help to explain local, spread, and widespread pressure hyperalgesia, and self-reported pain in people with PFP. BMI only helps to explain self-reported pain. These factors should be considered when assessing people with PFP and developing their management plan, but caution should be taken as the strength of association was generally low.

Bibliometric Analysis of Research on the Comorbidity of Pain and Inflammation

Objectives

To provide a comprehensive review on the global scientific research status of comorbid pain and inflammation from 1981 to 2019 and capture its subsequent development trends. Data Sources. The primary database chosen to collect publications on comorbid pain and inflammation research from 1981 to 2019 was the Web of Science (WOS). Core of the search strategy was the key word “pain” and the key word “inflammation” in the medical subject headings' major field. Study Selection. All articles retrieved were included in the bibliometric analysis. Data Extraction. We used CiteSpace to analyze publication outputs, subject categories, distribution by country/institution/journal, and other types of information. Then, knowledge base, hot issues, and future development directions were explained. Data Synthesis. A total of 2887 papers met the inclusion criteria in our research. Linear regression analysis results showed that the publications of studies of comorbid pain and inflammation significantly increased (P < 0.001) and have grown about 192 times in 40 years. The countries with the most outputs were the USA (886 publications), China (375 publications), and England (236 publications). Besides, Harvard University was the most prolific institution with 730 publications and 6646 citations. In accordance with the subject categories of WOS, neurosciences (31.832%), pharmacology/pharmacy (18.427%), and clinical neurology (15.206%) were the main research areas of these 2887 papers.

Conclusions

The current study reveals that research on comorbid pain and inflammation has gradually become more extensive worldwide since 1981, and neuropathic pain was the most popular study type. Most of our research output in this field came from countries in Europe and North America, although some Asian countries showed promising performance.