Lower-Extremity Muscle Activity, Kinematics, and Dynamic Postural Control in Individuals With Patellofemoral Pain

Hip and knee muscles co-activation ratio during hip-focused exercises: a multichannel surface electromyography study

This study aimed to evaluate the muscle activation ratio of hip and knee during hip-focused exercises. Eleven active university students performed 13 hip-focused exercises frequently used in the treatment of knee disorders. The average sEMG amplitude of tensor fasciae latae (TFL), gluteus medius (GMed), gluteus maximus (GMax), adductor longus (AL), vastus medialis (VM), vastus lateralis (VL), and GMed/AL, GMax/AL, and VL/VM ratios were determined. Repeated-measures analyses of variance were performed to determine if there were differences in muscle activation while performing each of the 13 exercises. Sidelying clam-shell had the highest GMax/AL ratio of all the exercises examined. The hip hike exercise (5.36) had the highest GMed/AL ratio. The VL/VM ratio ranged from 0.77 to 1.16. Based on these results, sidelying clam-shell had the highest GMax/AL ratio. The hip hike exercise had a higher GMed/AL ratio compared to other hip-focused exercises. Additionally, forward lunge, squat, and single-leg squat with resistance band around the knee had the highest activity VL/VM ratio among exercises.

Changes in Motor Strategy and Neuromuscular Control During Balance Tasks in People with a Bimalleolar Ankle Fracture: A Preliminary and Exploratory Study

Ankle fractures can lead to issues such as limited dorsiflexion, strength deficits, swelling, stiffness, balance disorders, and functional limitations, which complicate daily activities. This study aimed to describe neuromuscular adaptations at 6 and 12 months post-surgery during static and dynamic balance tasks, specifically using the Y-Balance Test (YBT). Additionally, the relationship between neuromuscular patterns, balance, and musculoskeletal deficits was evaluated. In 21 participants (14 at 6 months and 21 at 12 months) with bimalleolar fractures, hip strength, ankle dorsiflexion, ankle functionality, and static and dynamic balance were assessed using electromyography of five lower limb muscles (tibialis anterior, peroneus longus, lateral gastrocnemius, biceps femoris, and gluteus medius). A significant interaction effect (limb × proximal [hip]-distal [ankle] muscle) (F = 30.806, p < 0.001) was observed in the anterior direction of the Y-Balance Test (YBTA) at 6 months post-surgery. During the YBTA and YBT posteromedial (YBTPM), it was found that a lower dorsiflexion range of movement was associated specifically at 6 months with greater activation of the lateral gastrocnemius. However, these differences tended to diminish by 12 months. These findings suggest that neuromuscular patterns differ between operated and non-operated limbs during the YBTA at 6 months post-surgery. The Y-Balance Test, particularly its anterior direction, effectively highlighted these neuromuscular changes. This is a preliminary study; further research is needed to explore these findings in depth.

Comparison of hip abductors' strength and 2D frontal plane projection angle during two functional tests, in females with and without patellofemoral pain

INTRODUCTION

Hip abductors eccentrically maintain leg alignment during weight-bearing exercises. Hip abductors' weakness may be a significant aspect to take into account in the conservative management of Patellofemoral Pain (PFP). The aim of the study was to compare hip abductors' eccentric strength and hip kinematics during two functional tests, in female subjects with PFP.

METHOD

In a cross-sectional study using convenience sampling, isokinetic Isokinetic unilateral eccentric hip abductors' mean peak moment (MPM) at 60°/sec and Frontal Plane Projection Angle (FPPA) during Single-Leg Squat (SLS) and Single-Leg Landing (SLL) tests, were assessed in 17 asymptomatic individuals and 19 PFP patients.

RESULTS

The FPPA during SLL (p = 0.771) and SLS (p = 0.587), as well as the isokinetic values of the eccentric adductors' MPM at 60°/sec (p = 0.769), did not differ between the groups. The isokinetic values and the SLL (r = -0.009 to p = 0.970) and SLS (r = -0.002 to p = 0.993) in the PFP group and the control group (SLS r = 0.160 to p = 0.540) did not show any statistically significant relationships.

CONCLUSION

PFP and asymmetry in hip abduction strength are not substantially correlated. It is necessary to conduct more research to comprehend how these impairments interact and to find out if there are patient subgroups with PFP.

Effects of pain exacerbation on postural control in women with patellofemoral pain during single leg squat: a cross-sectional study

BACKGROUND

The center of pressure (COP) excursion parameters are recognized as risk factors for the etiology and development of patellofemoral pain (PFP). The purpose of the present study measures the effect of pain exacerbation on COP excursion, and the correlation between pain intensity and COP excursion in women with PFP during single leg squat (SLS).

METHODS

Sixty patients with PFP participated in this cross-sectional study. The outcome measures were included pain intensity and COP excursion which evaluated in pre and post pain exacerbation during SLS. The COP parameters were evaluated during single leg squat in 60° of knee flexion. A paired t-test and MANOVA was used to compare pain intensity and COP excursion between the two conditions, respectively. Furthermore, A Pearson's correlation matrix was used to examine the relationship between pain intensity with COP excursion.

RESULTS

Statistical analysis showed that pain intensity (t = - 16.655, p < 0.001) and COP excursion (Wilks' Lambda = 0.225, p < 0.001) with medium effect size increased after PFJ loading. In addition, an excellent positive correlation was observed between increased in pain intensity and COP excursion (P < 0.001, r > 0.80).

CONCLUSION

After PFJ loading, women with PFP presented increases in the pain intensity, COP excursions, and sway velocity. In addition, there was an association between the increase in pain intensity and COP excursions. Clinicians aiming to improve postural control of patients with PFP could use kinesio taping as a short-term intervention and balance training to improvements in postural control at medium and long-term. Furthermore, emphasizing psychological factors to reducing kinesiophobia can be useful to restoring proper movement pattern, reducing pain and improving symptoms.

Pain and disability were related to Y-balance test but not with proprioception acuity and single-leg triple-hop test in patients with patellofemoral pain: A cross-sectional study

INTRODUCTION

Patellofemoral pain is a common complaint between physically active subjects. Patients with patellofemoral pain present limitations to performing daily activities. Pain could alter proprioceptive acuity and lead to movement impairment. The aim of this study was to investigate the relationship of pain and disability with proprioception acuity and physical performance in patients with patellofemoral pain.

METHODS

Forty-eight patients with patellofemoral pain [age 31.15 (5.91) years; 30 (62.50%) males] were recruited. Data collected included pain intensity, pain duration, disability, joint position sense (JPS) test at 20° and 60° of knee flexion, and physical performance tests (Single-Leg Triple-Hop Test and Y- Balance Test). Spearman's rank correlation coefficient (rs) and 95% confidence intervals (CI) were computed to assess the relationship between the variables.

RESULTS

Pain intensity was correlated with Y-Balance Test posteromedial component (rs = -0.32, 95%CI = -0.55 to -0.03, p = 0.029) and the composite score (rs = -0.35, 95%CI = -0.58, -0.07, p = 0.015). Pain duration was correlated with Y-Balance Test posterolateral component (rs = -0.23, 95% CI = -0.53 to -0.01, p = 0.047). Disability was correlated with Y-Balance Test posteromedial component (rs = 0.41, 95% CI = 0.14 to 0.62, p = 0.004). Pain and disability were not correlated with JPS and the Single-Leg Triple-Hop Test.

CONCLUSION

Pain and disability were related to Y-Balance Test but not to proprioceptive acuity and Single-Leg Triple-Hop Test in patients with patellofemoral pain.

Clinic- and laboratory-based measures of postural control in patellofemoral pain: A systematic review with meta-analysis and evidence gap map

BACKGROUND

Patellofemoral pain (PFP) is a prevalent musculoskeletal disorder associated with functional impairments. Although postural control is commonly assessed in people with PFP, there are inconsistent results regarding potential postural control deficits in this population.

RESEARCH QUESTION

This review aims to evaluate whether postural control is impaired in people with patellofemoral pain (PFP) and the effectiveness of interventions on postural control measures.

METHODS

We searched six databases from their inception to May 5, 2023. We included studies assessing clinic- or laboratory-based postural control measures in people with PFP compared to pain-free controls, and intervention studies with PFP populations. We assessed risk of bias using the Joanna Briggs Institute critical appraisal checklists and the Cochrane Risk of Bias 2 tool. We assessed the certainty of evidence using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach. We used random-effects meta-analyses considering subgroups based on type of task, measure, and intervention.

RESULTS

Fifty-three studies were included. Very low certainty evidence indicated that people with PFP have shorter anterior (SMD = 0.53, 95 %CI:0.16,0.90), posteromedial (SMD = 0.54, 95 %CI:0.04,1.03) and posterolateral (SMD = 0.59, 95 %CI:0.11,1.07) reach distance, and worse composite score (SMD = 0.46, 95 %CI:0.22,0.70). Very low to moderate certainty evidence indicated that people with PFP have worse anterior-posterior and overall stability indexes during single-leg stance (SMD = -0.71, 95 %CI:-1.29,-0.14; SMD = -0.63, 95 %CI:-0.94,-0.32) and overall stability index during double-leg stance (SMD = -0.39, 95 %CI:-0.78,-0.00), but no differences in center of pressure area during stair ascent (SMD = 0.32, 95 %CI:-2.72, 3.36). Low certainty evidence indicated that kinesio taping improved anterior reach distance (SMD = -0.49, 95 %CI:-0.89,-0.09), while no significant differences were observed between pre- and post-intervention outcomes for conventional rehabilitation and rigid taping.

SIGNIFICANCE

Clinicians should use clinic- (star excursion or Y-balance tests) and laboratory-based (stability indexes) measures to identify impairments of postural control in people with PFP. Low certainty of evidence suggests short-term improvement in postural control with kinesio taping.

Is Postural Control Affected in People with Patellofemoral Pain and Should it be Part of Rehabilitation? A Systematic Review with Meta-analysis

BACKGROUND

Growing evidence supports that exercise therapy is effective for patellofemoral pain (PFP) rehabilitation. Nevertheless, the improvements have been reported not to be sustained in the long term, suggesting that the current protocols may not comprehend all required functional factors to provide a consistent recovery. A potential neglected factor in treatment protocols for PFP is postural control. However, it is unclear whether this population presents balance impairments or the influence of postural control on pain and function during rehabilitation programmes.

OBJECTIVE

To investigate whether (Q1) balance is impaired in people with PFP compared to controls, (Q2) conservative interventions are effective to improve balance in people with PFP, and (Q3) balance exercises are effective to improve pain and function in people with PFP.

DATA SOURCES

Medline, Embase, CINAHL, SPORTDiscus, Web of Science and Cochrane Library, supplemented by hand searching of reference lists, citations and relevant systematic reviews in the field.

METHODS

A systematic review with meta-analysis was conducted according to the Cochrane recommendations and reported according to the PRISMA statement recommendations. We included cross-sectional studies comparing balance between people with and without PFP; and randomised controlled trials verifying the effect of conservative intervention on balance and the effect of balance intervention on pain and function in people with PFP. The risk of bias was assessed using the Epidemiological Appraisal Instrument for cross-sectional studies and the Physiotherapy Evidence Database scale for randomised controlled trials.

RESULTS

From 15,436 records, 57 studies (Q1 = 28, Q2 = 23, Q3 = 14) met the eligibility criteria. Meta-analyses indicated that people with PFP have worse anteroposterior (very low grade evidence, standardised mean difference [SMD] = 1.03, 95% CI 0.40-1.66) and mediolateral (moderate grade evidence, SMD = 0.87, 95% CI 0.31-1.42) balance compared to controls. Moderate grade evidence indicated that overall balance is not affected in people with PFP (SMD = 0.38, 95% CI - 0.05-0.82). Low to very low grade evidence indicates that interventions are ineffective for mediolateral (SMD = 0.01, 95% CI - 0.51-0.53) and overall (SMD = 0.49, 95% CI - 0.14-1.11) balance improvements, and low grade evidence indicates that interventions are effective to improve anteroposterior balance (SMD = 0.64, 95% CI 0.04-1.23). Moderate to low grade evidence indicated that balance interventions are effective to reduce pain (SMD = 0.82, 95% CI 0.26-1.38) and improve function (SMD = 0.44, 95% CI 0.09-0.80) when measured using questionnaires; and very low grade evidence indicated no efficacy for function measured via functional tests (SMD = 0.73, 95% CI - 0.16-1.61).

CONCLUSION

People with PFP likely present balance deficits compared to asymptomatic people. There was insufficient evidence to support the efficacy of interventions to improve or modify balance in people with PFP. Also, there was insufficient evidence to support the efficacy of balance exercises to improve pain and function in people with PFP. Trial Registration The present systematic review was registered in PROSPERO (CRD42018091717).

Female athletes with ligament dominance exhibiting altered hip and ankle muscle co-contraction patterns compared to healthy individuals during single-leg landing

BACKGROUND

Anterior cruciate ligament (ACL) injury is one of the most serious knee injuries and occurs frequently during exercise. Altered hip and ankle muscle co-contraction patterns may contribute to dynamic knee valgus and ACL injury mechanisms. Lack of dynamic control of ground reaction force (GRF) is known to be contributing factor for ACL injury by placing excessive force on passive structures. Muscle co-contraction is a dynamic mechanism for GRF absorption. Therefore, any alterations in co-contraction might be a risk factor for ACL injury. Ligament dominance is a term to define individuals who rely more on ACL ligament for GRF control.

RESEARCH QUESTION

This study aimed to compare the muscle co-contraction patterns of distal and proximal knee muscles during single leg landing in female athletes with and without ligament dominance.

METHODS

This is a cross-sectional study. A total of 54 female athletes were assigned to the healthy (n = 27) and ligament dominance (n = 27) group based on their Tuck Jump test scores. The electromyography activity of the gluteus medius, adductor longus, tibialis anterior, peroneus longus, medial and lateral gastrocnemius was measured by an electromyography in drop down a 30-cm-high stair. A Multivariate Analysis of Variance (MANOVA) was used for statistical analysis (p ≤ 0.05).

RESULTS

The two groups demonstrated an overall significantly different muscle co-contraction patterns (P < 0.05). There was a decreased in co-contraction of proximal group and an increased co-contraction in the distal muscles in ligament dominant group.

SIGNIFICANCE

The findings have provided evidence to support the notion of neuromuscular imbalances in ligament dominance deficit. These findings can be useful for the coaches and experts to design preventive exercises and modify the current programs for the people affected by ligament dominance.

SEBT in individuals with patellofemoral pain: an integrative review

Abstract Introduction: Decreased postural stability can be observed in individuals with patellofemoral pain (PP). The Star Excursion Balance Test (SEBT) is widely used to assess deficits that need to be improved, with different application methods and result presentation formats. Objective: To map SEBT use in individuals with PP, characterizing the studies that applied it to identify different application methods and result presentation formats. Methods: The review included randomized and non-randomized clinical trials, cross-sectional, case-control and cohort studies. Searches were performed in Pubmed and SciElo databases. Data extracted from eligible studies were divided into categories: (I) study characterization (II) SEBT application methods and result presentation formats. Results: A total of 177 studies were identified in the databases, 13 of which were selected. There are a growing number of new studies that assess the dynamic postural control of individuals with PP using the SEBT, and a variety of test application and result presentation formats. Conclusion: The SEBT is a useful, easy-to-apply test that identifies changes in dynamic postural control in individuals with PP. Different application and result presentation formats are in accordance with the literature, but it is recommended that future studies apply the protocols most widely used in previous studies that exhibit a low risk of bias, in order to improve repeatability and comparisons between studies.

Local neuromuscular characteristics associated with patellofemoral pain: A systematic review and meta-analysis

BACKGROUND

Local neuromuscular deficits have been reported in people with patellofemoral pain. We synthesised the neuromuscular characteristics associated with patellofemoral pain to help identify interventional targets and potential mechanisms.

METHODS

Five databases were searched for local neuromuscular characteristics in case-control studies. Electromyography, flexibility, muscle performance and cross-sectional area data were derived from functional or isolated task investigations and synthesised accordingly. An evidence gap map was constructed.

FINDINGS

Sixty-seven studies were included. In functional tasks, electromyographic investigations showed moderate evidence of small effect for vastus medialis onset-delays relative to vastus lateralis (0.44 [0.03, 0.85]) during stepping/stair negotiation tasks, and higher biceps femoris mean excitation amplitudes (0.55 [0.06, 1.04]) in single-leg triple-hop test. In isolated tasks, we found moderate evidence of medium effect for lower Hoffman-reflex amplitude of vastus medialis (-1.12 [-1.56, -0.67]). Muscle performance investigations showed; strong evidence with medium and small effects for lower extensors concentric (-0.61 [-0.81, -0.40]) and eccentric (-0.56 [-0.79, -0.33]) strength, and moderate evidence of medium effect of lower isometric (-0.64 [-0.87, -0.41]) strength, moderate evidence with small effect for rate of force development to 30% (-0.55[-0.89, -0.21]), 60% (-0.57[-0.90, -0.25]) and medium effect to 90% (-0.76[-1.43, -0.10]) of maximum voluntary contraction, and small effect for lower flexors concentric strength (-0.46 [-0.74, -0.19]) and extensors total work (-0.48 [-0.90, -0.07]). Flexibility investigations showed tighter hamstrings (-0.57 [-0.99, -0.14]).

INTERPRETATION

Differences within quadriceps and hamstrings motor-control, hamstrings tightness, and quadriceps and hamstrings weakness are associated with patellofemoral pain, and can be used to guide investigations of treatment effects.

Knee proprioceptive function and physical performance of patients with patellofemoral pain: A matched case-control study

BACKGROUND

Patients with patellofemoral pain (PFP) present pain, functional limitation, and alteration in knee proprioception.

PURPOSE

To compare the knee joint position sense and lower extremity functionality between patients with PFP and controls. Secondarily, investigate the relationship between proprioceptive acuity and physical performance.

METHODS

This is a matched case-control study including 48 patients with PFP and 48 healthy individuals matched by age, sex, weight, height, and limb dominance. The proprioceptive evaluation was performed using the joint position sense test (absolute error and relative error) and functionality was assessed using the Single-Leg Triple-Hop test and the Y-Balance Test. The groups were compared using the independent student's T-test. Proprioceptive acuity and physical performance correlations were determined by Pearson correlation coefficient.

RESULTS

Participants were on average 31 years old and 62.5% were men. There was no statistically difference for absolute and relative angular error between groups. Patients presented lower relative reached distance on the anterior direction of the Y-Balance Test than controls [patients=58.6 (6.6) % versus controls=61.7 (5.9) %, p=.020]. No differences between groups were found for other functional measures. Significant correlation was found between absolute angular error and anterior component at 60° (r=0.225, p=.028) and relative angular error at 60° with the posterolateral component of the Y- Balance Test (r=0.231, p=.024).

CONCLUSION

Proprioceptive acuity of patients with PFP was not reduced. The anterior direction of the Y-Balance Test was impaired compared to matched controls. Proprioceptive sense is related to dynamic balance but not to jump ability.

The 45-second anterior knee pain provocation test: A quick test of knee pain and sporting function in 10-14-year-old adolescents with patellofemoral pain

OBJECTIVE

To test 1) if the 45-second Anterior Knee Pain Provocation Test (AKPP-test) could differentiate between adolescents with patellofemoral pain (PFP) and pain-free controls and; 2) whether improvements in the AKPP-test over 12 weeks were associated with improvements in self-reported knee function and pain.

DESIGN

Prospective cohort.

PATIENTS

151 with PFP and 50 pain-free controls (age 10-14 years).

OUTCOMES

The AKPP-test was performed at baseline, 4- and 12-week follow-up. Pain and function were collected using Knee Injury and Osteoarthritis Outcome Score (KOOS).

RESULTS

At baseline, the AKPP-test provoked pain to a median of 5 points (IQR: 3-7) on the 0-10 Numeric Pain Rating Scale in adolescents with PFP, compared to 0 (IQR 0-0) in controls. Higher pain during the AKPP-test was associated with worse KOOS-Sport/Rec (r = -0.33, P < 0.001), worse KOOS-Pain (r = -0.47, P < 0.001), and pain intensity (worst pain last 24 hours) (r = -0.39, P < 0.001) at baseline. Improvements in the AKPP-test over 12 weeks were associated with improvements in KOOS Pain (r = 0.48, P < 0.001) and KOOS Sport/Rec (r = 0.40, P < 0.001).

CONCLUSIONS

Improvements in the AKPP-test were associated with improvements in self-report knee pain and limitations in sports, suggesting the AKPP-test may be a clinically responsive test of knee pain and sporting function in adolescents with PFP.