Quadriceps or hip exercises for patellofemoral pain? A randomised controlled equivalence trial.

OBJECTIVE: To assess effectiveness equivalence between two commonly prescribed 12-week exercise programmes targeting either the quadriceps or the hip muscles in patients with patellofemoral pain (PFP). METHODS: This randomised controlled equivalence trial included patients with a clinical diagnosis of PFP. Participants were randomly assigned to either a 12-week quadriceps-focused exercise (QE) or a hip-focused exercise (HE) programme. The primary outcome was the change in Anterior Knee Pain Scale (AKPS) (0-100) from baseline to 12-week follow-up. Prespecified equivalence margins of ±8 points on the AKPS were chosen to demonstrate comparable effectiveness. Key secondary outcomes were the Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire pain, physical function and knee-related quality of life subscales. RESULTS: 200 participants underwent randomisation; 100 assigned to QE and 100 to HE (mean age 27.2 years (SD 6.4); 69% women). The least squares mean changes in AKPS (primary outcome) were 7.6 for QE and 7.0 for HE (difference 0.6 points, 95% CI -2.0 to 3.2; test for equivalence p<0.0001), although neither programme surpassed the minimal clinically important change threshold. None of the group differences in key secondary outcomes exceeded predefined equivalence margins. CONCLUSION: The 12-week QE and HE protocols provided equivalent improvements in symptoms and function for patients with PFP. TRIAL REGISTRATION NUMBER: NCT03069547.

Custom-Made Foot Orthoses Decrease Medial Foot Loading During Drop Jump in Individuals With Patellofemoral Pain.

OBJECTIVE: To investigate the effect of foot orthoses on medial-to-lateral plantar forces during drop jump and single leg squat, and second, to explore the self-reported change in symptoms after 12 weeks of wearing the orthoses in individuals with patellofemoral pain (PFP). DESIGN: Cohort study with 12 weeks of follow-up. SETTING: Hospital setting. PARTICIPANTS: 23 adults with PFP. INTERVENTIONS: Custom-made foot orthoses. MAIN OUTCOME MEASURES: Foot loading (plantar pressure) was collected from the most painful side during drop jump and single leg squat using pressure sensitive Pedar insoles. Primary outcome was the medial-to-lateral peak force under the forefoot during drop jump. The PFP syndrome severity score was used to measure self-reported improvement from baseline to follow-up. RESULTS: Orthoses were associated with a significant 2.9%-point (95% confidence intervals: 0.7-5.1) reduction in peak medial-to-lateral force during drop jump. Individuals with a self-reported improvement after 12 weeks had a significant 4.2%-point larger reduction in medial-to-lateral foot loading during drop jump. CONCLUSIONS: This preliminary study showed that foot orthoses were associated with a decrease in medially directed foot loading among individuals with PFP. Individuals, who have an immediate decrease in the medial-to-lateral peak force after fitting the orthoses, were more likely to report improvements after 12 weeks of use.

Increased medial foot loading during drop jump in subjects with patellofemoral pain.

PURPOSE: To compare medial-to-lateral plantar forces during drop jump and single leg squat in individuals with and without patellofemoral pain. METHODS: This cross-sectional study compared 23 young adults with patellofemoral pain to 20 age- and sex-matched controls without knee pain. The plantar pressure distribution was collected during drop jump and single leg squat using pressure-sensitive Pedar insoles, inserted into a standard flat shoe. The primary outcome was the medial-to-lateral force, quantified as the peak force under the medial forefoot as the percentage of force under the total forefoot during drop jump. Secondary outcomes included peak medial-to-lateral force during single leg squat and mean forces during drop jump and single leg squat. RESULTS: The primary outcome showed that individuals with patellofemoral pain had a 22% higher medial-to-lateral peak force during drop jump, (p=0.03). Secondary outcomes showed 32% higher medial-to-lateral peak force during single leg squat (p=0.01) and 19-23% higher medial-to-lateral mean force during drop jump and single leg squat (p=0.02-0.04). CONCLUSION: These findings indicate that individuals with patellofemoral pain display a more medially oriented loading pattern of the forefoot compared to individuals without knee pain. This loading pattern may be associated with the distribution of forces acting on the patellofemoral joint and suggest treatment of PFP should consider interventions that target normalisation of foot loading. LEVEL OF EVIDENCE: III.

Physical therapists' prognosis of outcomes after a hip or quadriceps exercise intervention in patients with patellofemoral pain: A secondary analysis of a randomized trial.

OBJECTIVE: Can physical therapists who are treating patients with Patellofemoral Pain (PFP) predict the outcome of a 12-week exercise intervention based on initial assessment, and what are the physical therapists' reasons for prediction? DESIGN: Secondary analysis of a randomized trial. METHODS: After the initial assessment, physical therapists were asked to predict the prognosis of 200 patients with PFP who were allocated to 12 weeks of quadriceps exercises (QE) or hip exercises (HE) on a 1-10 Likert scale, and to describe their reasoning for the prediction score. Outcome measures were changes from baseline to week 12 and 26 on the Anterior Knee Pain Scale (AKPS; range 0-100) and a transition questionnaire (TransQ). Linear mixed-effects models were used to assess the prediction. Secondly, we used a qualitative approach to summarize the physical therapists' reasoning (written notes) when predicting the outcome. RESULTS: There was no association between physical therapists' prognosis and changes in AKPS for QE or HE at week 12 and 26 (Slopes: -0.14 to -0.51 with wide 95% confidence intervals [CI]). There was no association between physical therapists' assessment of prognosis using TransQ for QE or HE at week 12 and 26 (OR: 0.99 to 1.17 with wide 95% CIs). physical therapists. CONCLUSION: Physical therapists' prognosis based on initial assessment was not associated with outcomes after weeks 12 of either quadriceps or hip exercise-therapy among patients with PFP. Physical therapists' prognoses were not useful as a source of information and to identify PFP patients with poor or good projected outcomes.

The COVID-19 in athletes (COVA) study: a national study on cardio-pulmonary involvement of SARS-CoV-2 infection among elite athletes.

Background: COVID-19 can cause cardiopulmonary involvement. Physical activity and cardiac complications can worsen prognosis, while pulmonary complications can reduce performance. Aims: To determine the prevalence and clinical implications of SARS-CoV-2 cardiopulmonary involvement in elite athletes. Methods: An observational study between 1 July 2020 and 30 June 2021 with the assessment of coronary biomarkers, electrocardiogram, echocardiography, Holter-monitoring, spirometry, and chest X-ray in Danish elite athletes showed that PCR-tested positive for SARS-CoV-2. The cohort consisted of male football players screened weekly (cohort I) and elite athletes on an international level only tested if they had symptoms, were near-contact, or participated in international competitions (cohort II). All athletes were categorized into two groups based on symptoms and duration of COVID-19: Group 1 had no cardiopulmonary symptoms and duration ≤7 days, and; Group 2 had cardiopulmonary symptoms or disease duration >7 days. Results: In total 121 athletes who tested positive for SARS-CoV-2 were investigated. Cardiac involvement was identified in 2/121 (2%) and pulmonary involvement in 15/121 (12%) participants. In group 1, 87 (72%), no athletes presented with signs of cardiac involvement, and 8 (7%) were diagnosed with radiological COVID-19-related findings or obstructive lung function. In group 2, 34 (28%), two had myocarditis (6%), and 8 (24%) were diagnosed with radiological COVID-19-related findings or obstructive lung function. Conclusions: These clinically-driven data show no signs of cardiac involvement among athletes who tested positive for SARS-CoV-2 infection without cardiopulmonary symptoms and duration <7 days. Athletes with cardiopulmonary symptoms or prolonged duration of COVID-19 display, exercise-limiting cardiopulmonary involvement.

Reliability and normative values of the foot line test: a technique to assess foot posture.

STUDY DESIGN: Test-retest reliability. OBJECTIVE: To examine the reliability and report normative values of a novel test, the foot line test (FLT), to describe foot morphology. BACKGROUND: Numerous foot examinations are performed each day, but most existing examination techniques have considerable limitations regarding reliability and validity. METHODS: One hundred thirty subjects with mean foot size 44 (41-50 European size) participated. Two examiners, blinded to each other's measurements, measured the right foot of the subjects twice and the left foot once. The position of the most medial aspect of the navicular in the mediolateral direction was projected vertically onto a piece of paper placed under the subject's foot, and compared to the position of the forefoot and hindfoot to obtain the FLT value. RESULTS: FLT values ranged from -8 to 14 mm, with a mean (+/-SD) of 3.7 +/- 3.4 mm. The intratester reproducibility reported by SEM was 0.8 mm for tester 1 and 0.9 mm for tester 2, while intertester SEM was 1.4 mm for the right foot and 1.3 mm for the left foot. The intrarater ICC was 0.95 for tester 1 and 0.94 for tester 2, while the interrater ICC was 0.86 (left foot) and 0.83 (right foot). There was no significant association between foot size and FLT values. CONCLUSION: The FLT is a reproducible technique to assess foot posture.

Prevention of overuse injuries by a concurrent exercise program in subjects exposed to an increase in training load: a randomized controlled trial of 1020 army recruits.

BACKGROUND: It is unknown whether an exercise program can prevent overuse injuries in the lower extremity. An often encountered and important risk factor for the development of lower extremity overuse injuries is an abrupt increase in activity level. HYPOTHESIS: A preventive training program based on a literature review of intrinsic risk factors, and performed concurrent with an increase in physical activity, can reduce the incidence of overuse knee injuries and medial tibial stress syndrome, as well as increase running distance. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: A total of 1020 soldiers aged 20.9 years (range, 19-26 years) undergoing 3 months of basic military training consecutively enrolled from December 2004 to December 2005. The prevention program consisted of an exercise program of 15 minutes' duration 3 times a week, including 5 exercises for strength, flexibility, and coordination; the placebo program consisted of 5 exercises for the upper body. RESULTS: During the observation period, 223 subjects sustained an injury, with 50 and 48 of these fulfilling the study criteria for overuse knee injuries or medial tibial stress syndrome, respectively. There were no significant differences in incidence of injury between the prevention group and the placebo group (incidence, 0.22 vs 0.19; P = .162; relative risk = 1.05 [range, 0.98-1.11]). The soldiers in the prevention group had the greater improvement in running distance in 12-minute run tests (82 vs 43 m; P = .037). CONCLUSION: An exercise program with an emphasis on muscular strengthening, coordination, and flexibility based on intrinsic risk factors identified through a literature review did not influence the risk of developing overuse knee injuries or medial tibial stress syndrome in subjects undergoing an increase in physical activity. The program increased maximal running distance in a 12-minute test.