The relationship between acute pain and dynamic postural stability indices in individuals with patellar tendinopathy

Relationship between exacerbating patellofemoral pain and dynamic knee valgus in females with patellofemoral pain after a patellofemoral joint loading protocol: A cross-sectional

OBJECTIVE

The aim of the present study is to 1) the effect of exacerbating patellofemoral pain (PFP) on dynamic knee valgus (DKV) 2) the relationship between exacerbating PFP and DKV in females with patellofemoral pain.

DESIGN

Cross-sectional study.

METHODS

Sixty women with PFP were recruited from the orthopedic clinics. We evaluated pain intensity and DKV in two conditions without (condition 1) and with (condition 2) PFJ loading during the single-leg squat (SLS) task. The MANOVA test was used to compare pain intensity and DKV angle between the two conditions. Furthermore, the Pearson correlation was used to examine the correlation between pain intensity with DKV angle.

RESULTS

The MANOVA analysis showed that pain intensity (P < 0.000, η2 = 0.623) and DKV angle (P < 0.000, η2 = 0.544) with a medium effect size significantly increased after PFJ loading. Furthermore, an excellent positive correlation was observed between an increase in pain intensity and DKV angle (P < 0.000, r = 0.840).

CONCLUSION

It seems that after the PFJ loading protocol and the subsequent pain exacerbation, the neuromuscular biomechanics of the lower limb are deficits. As a result, the stabilizing muscles activation decreases and increases the lower limb movement in the frontal plane.

Relationship Between Postural Stability and Proprioception, Pain, Quadriceps Strength, and Muscle Tightness in Athletes With Patellar Tendinopathy

BACKGROUND

Athletes with patellar tendinopathy (PT) have postural stability deficits; however, the underlying mechanisms and factors responsible remain unknown. The effect on postural stability in PT of decreased quadriceps strength, altered proprioception, lower-limb muscle tightness, and knee pain, which explain postural stability deficiency in other populations, is uninvestigated.

HYPOTHESIS

Proprioceptive acuity, muscle tightness, quadriceps strength, and pain predict postural stability in athletes with PT.

STUDY DESIGN

Cross-sectional comparative study.

LEVEL OF EVIDENCE

Level 2.

METHODS

A total of 43 athletes with PT and 43 healthy athletes were enrolled. Static and dynamic postural stability, proprioceptive acuity, muscle tightness, quadriceps strength, and pain were evaluated using a force platform, Y-balance test (YBT), a weight discrimination protocol, a goniometer, an isometric dynamometer, and a valid questionnaire, respectively.

RESULTS

Athletes with PT had significantly worse static and dynamic postural stability in the affected limb (AL) compared with the nonaffected limb (NAL) (P < 0.01) and the control group (P < 0.01). Athletes suffering from PT revealed lower quadriceps strength (P < 0.01), proprioceptive acuity (P = 0.02), and higher muscle tightness in the AL compared with the NAL and controls. Quadriceps weakness of the AL and pain in athletes with PT explained the variance of dynamic postural stability impairment.

CONCLUSION

Athletes with PT have postural stability deficiency compared with healthy peers. Our results demonstrate that quadriceps muscle weakness and pain are the factors that explain postural stability impairment.

CLINICAL RELEVANCE

These results can assist clinicians in the design of therapeutic balance rehabilitation programs by acting not only on pain relief but also on quadriceps strengthening through resistance training to avoid subsequent injuries in athletes with PT.

Patellar tendinopathy impairs postural control in athletes: A case-control study

OBJECTIVE

To compare postural control performance between athletes with and without patellar tendinopathy (PT).

DESIGN

Case-control study.

PARTICIPANTS

Fifty-eight athletes, 29 with PT (PT group: PTG) and 29 healthy ones (control group: CG).

MAIN OUTCOME MEASURES

Static and dynamic postural control were assessed with a force platform and the Y-Balance Test (Y-BT), respectively. Quadriceps strength of both limbs was evaluated using an isometric dynamometer.

RESULTS

The PTG exhibited significantly (p < 0.05) higher centre of pressure (CoP) values than the CG on the foam surface, and significantly lower (p < 0.001) anterior, posteromedial and posterolateral normalized reach distances, and composite score in dynamic postural control on the injured limb (IL) compared to non-injured limb (NIL) and dominant limb (DL) of the CG. The quadriceps muscle strength was significantly lower on the IL compared to the NIL (p < 0.01) and DL (p < 0.05) of the CG.

CONCLUSION

Athletes suffering from PT exhibited worse static and dynamic postural control compared to healthy peers. As players with PT frequently continue training despite their tendon pain, physiotherapists and clinicians should incorporate balance rehabilitation programs in the treatment of these players, not only to prevent further potential injuries but also to enhance sport performance.

Athletes with unilateral patellar tendinopathy have increased subsequent lower extremity musculoskeletal injury risk

This study aimed to investigate static and dynamic postural balance inter-limb asymmetries in athletes with unilateral patellar tendinopathy (UPT) and estimate subsequent lower extremity musculoskeletal injury risk compared to controls. Twenty-eight athletes with UPT were recruited. Twenty-eight healthy athletes served as controls. Static postural balance inter-limb asymmetry (symmetry index: SI) was assessed based on differences in the mean centre of pressure (CoP) velocity (CoP_v) values between the affected leg (AL) and non-affected leg (NAL) for the UPT group, and the dominant leg (DL) and non-dominant leg (NDL) for controls. Outcome variables were dynamic postural balance, assessed with inter-limb asymmetry using the Y Balance Test (YBT), and injury risk. In static balance, SI values were significantly (P<0.001) higher in the UPT group compared to controls. In dynamic balance, normalized inter-limb asymmetry values were also significantly higher in athletes with UPT compared to controls in anterior (P<0.001), posteromedial (P<0.001) and posterolateral (P<0.01) directions, and in the composite score (P<0.001). Furthermore, the incidence of sustaining a non-contact lower extremity injury during the follow-up period (10 months) was significantly higher (P<0.05) in the UPT group compared to controls. Athletes with UPT had postural balance inter-limb asymmetries. Moreover, they had increased subsequent lower extremity musculoskeletal injury risk compared to controls. Since most athletes with UPT continue to train and compete, adequate training and rehabilitation programmes should be implemented to prevent potential subsequent injury occurrence.

Current Clinical Concepts: Clinical Management of Patellar Tendinopathy

Patellar tendinopathy is a common, yet misunderstood pathoetiology afflicting a variety of patient populations. This lack of unified understanding affects the capability of clinicians to provide effective treatment interventions. Patients with tendinopathy often report long-term and low to moderate levels of pain, diminished flexibility, and strength, as well as decreased physical function. Load-management strategies combined with exercise regimens focused on progressive tendon loading are the most effective treatment option for patients with patellar tendinopathy. This review will provide an evidence-based approach to patellar tendinopathy, including its pathoetiology, evaluation, and treatment strategies.

Proposal for a Clinical Analysis of Patellar Tendon Pathologies: In Search of Efficient Therapeutic Indications

Development and advances in our understanding of basic sciences such as anatomy, biochemistry, histology, and biomechanics have led to a better knowledge of tendon injuries. Likewise, technological advances in available therapies have conditioned the rise of new therapeutic techniques, turning both diagnosis and therapeutic indications into the foundation of treatment for patellar tendon disorders. Furthermore, we often find no correlation between patellar tendon function and structure, as studied and diagnosed from images taken and referred symptoms. This statement proposes an analytic procedure that ensures a specific therapeutic goal instead of applying a specific drug or therapeutic technique, with the aim of establishing parameters that define the kind of tendinopathy clinicians see, taking into account all conditioning factors that may affect a patellar tendinopathy. These include etiological factors, systemic illnesses affecting tendons, local mechanical causes and clinical presentation, range of clinical presentations, symptom persistence, and pain location, as well as those factors described by echography, with or without the presence of neoangiogenesis and location of the pathology, and magnetic resonance imaging. Diagnosing patellar tendinopathies requires deployment of a complex and thorough assessment process for each individual case and should include all variables that basic sciences have provided. Once a diagnosis has been made, a therapeutic strategy that includes all existing variables should be established. The more precise a diagnosis is, the more selective the treatment options become.