Início da atividade elétrica dos músculos estabilizadores da patela em indivíduos com SDPF

Efficacy of Different Cold-Water Immersion Temperatures on Neuromotor Performance in Young Athletes

Cold-Water-Immersion (CWI) has been frequently used to accelerate muscle recovery and to improve performance after fatigue onset. In the present study, the aim was to investigate the effects of different CWI temperatures on neuromuscular activity on quadriceps after acute fatigue protocol. Thirty-six young athletes (16.9 ± 1.4 years-old; 72.1 ± 13.8 kg; 178.4 ± 7.2 cm) were divided into three groups: passive recovery group (PRG); CWI at 5 °C group (5G); and CWI at 10 °C group (10G). All participants performed a fatigue exercise protocol; afterwards, PRG performed a passive recovery (rest), while 5G and 10G were submitted to CWI by means of 5 °C and 10 °C temperatures during 10 min, respectively. Fatigue protocol was performed by knee extension at 40% of isometric peak force from maximal isometric voluntary contraction. Electromyography was used to evaluate neuromuscular performance. The passive recovery and CWI at 5 °C were associated with normalized isometric force and quadriceps activation amplitude from 15 until 120 min after exercise-induced fatigue (F = 7.169, p < 0.001). CWI at 5 °C and 10 °C showed higher muscle activation (F = 6.850, p < 0.001) and lower median frequency (MF) than passive recovery after 15 and 30 min of fatigue (F = 5.386, p < 0.001). For neuromuscular efficiency (NME) recovery, while PRG normalized NME values after 15 min, 5G and 10G exhibited these responses after 60 and 30 min (F = 4.330, p < 0.01), respectively. Passive recovery and CWI at 5 °C and 10 °C revealed similar effects in terms of recovery of muscle strength and NME, but ice interventions resulted in higher quadriceps activation recovery.

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.

Electromyographic activity of the quadriceps and gluteus medius muscles during/different straight leg raise and squat exercises in women with patellofemoral pain syndrome

Patellofemoral pain syndrome (PPS) is characterized by anterior knee pain and affects young female adults. Physiotherapy is the most indicated treatment. The objective of the study was to analyze electromyographic activity of the quadriceps and gluteus medius muscles during different open and closed kinetic chain exercises in women with PPS. Twenty-two clinically healthy women and 24 women with symptomatic PPS were assessed through surface electromyography of the quadriceps and gluteus medius during the following exercises: straight leg raise with and without lateral hip rotation; squats; squats with adduction and hip abduction; and squats combined with lateral hip rotation. When comparing the groups, only the quadriceps muscle showed higher activity in the PPS group. In the comparisons between the exercises, in relation to gluteus medius and quadriceps muscle activity, the straight leg raise and straight leg raise with lateral hip rotation exercises showed more activity than squats in both groups. Among the squats, squats with adduction generated more gluteus medius activity in both groups, and no difference was noted among the squats for the quadriceps muscle. Therefore, rehabilitation programs that include exercises such as straight leg raises, straight leg raises with lateral hip rotation, and squats with adduction may be used for PPS patients.

Analysis of pain, functional capacity, muscular strength and balance in young women with Patellofemoral Pain Syndrome

Abstract Introduction: Patellofemoral Pain Syndrome (PFPS) is associated with anterior knee pain, changes in functional capacity, balance and muscle strength disorders. Objective: To quantify pain, functional capacity, strength in quadriceps (Q), gluteus medium (GM), hip external rotator (ER) muscles and balance in sedentary women with PFPS. Methods: Twenty sedentary women, aged 18 to 25 years, were divided into two groups: PFPS (N=10) and control group (N=10). All the volunteers answered the items of the Visual Analogue Scale (VAS), the Lysholm Knee Score Scale, the Anterior Knee Pain Scale (AKPS), and the Lower Extremity Functional Scale (LEFS). The participants performed the following tests: maximal voluntary isometric contraction measured by dynamometry; postural balance using the Star Excursion Balance Test (SEBT) and a force platform. Statistical analyses were performed using the Shapiro Wilk test, the Mann Whitney U test and Spearman’s correlation coefficient. Data were submitted to SPSS 20 software. Results: The PFPS group presented greater pain, balance impairment and higher average velocity of oscillation; however, no differences were observed in Q, GM and RE muscle strength and in balance analyzed by SEBT. Conclusion: Women with PFPS exhibited greater pain, worse functional capacity and body balance. Moderate correlation between both balance tests suggests the use of SEBT when the force platform is not available, which could facilitate and highlight the importance of clinical diagnosis with regard to postural balance.

The Effect of Increasing Volume of Exercise on Activation Pattern of Vastus Medialis and Lateralis and its Correlation With Anterior Knee Pain in Karate Elites

Background

The effects of exercise volume on the pattern of muscle activity is one of the most important factors in training management and injury risk reduction. In the lower limb, the quadriceps muscle which plays a determining role in performing the stance and other karate techniques could be injured in intensive exercise and may induce anterior knee pain in athletes.

Objectives

The aim of this study was to determine the relationship between training volume and muscle activity of vastus medialis and vastus lateralis and its association with anterior knee pain in karate elites.

Patients and Methods

Male and female athletes from national junior and cadet karate team (14 to 18 years) were invited to participate in the study at the beginning and the end of the training camps. Studies involved measurement of electromyographic muscle activity of vastus medialis and vastus lateralis in both lower extremities with surface electromyography device and assessment of movement by electrogoniometery. Muscle activity was recorded in three tests of dachi, walking up and walking down stairs. Simultaneously, anterior knee pain was evaluated using visual analogue scale and anterior knee pain scale questionnaire.

Results

Eight athletes of a total number of 23 reported increased ratings of pain in their right knees. No differences in muscle activity were observed in tests of Dachi and stairs between the groups with and without pain. Comparing Dachi task pattern at the beginning and end of training camps, there was no significant difference in pattern of biomechanical movement; however, reducing the amount of muscle activity in early and late phases of tasks was observed in electromyographic assessment.

Conclusions

The results showed that performing the same task after a six-week training period, less muscle activity was required in all phases in two groups of tasks, including karate-specific movement (dachi) and activities of daily living (up or down stairs).

Influência do calçado de salto alto na atividade eletromiográfica do músculo quadríceps em mulheres com e sem síndrome da dor femoropatelar durante a tarefa de levantar e sentar

O objetivo do estudo foi analisar a influência do calçado de salto alto na atividade eletromiográfica (EMG) do músculo quadríceps durante a tarefa de sentar e levantar. Participaram deste estudo 10 voluntárias assintomáticas com 20,2±3,0 anos e 10 voluntárias com síndrome da dor femoropatelar (SDFP) com 21,3±3,4 anos. As voluntárias executaram a tarefa de sentar e levantar em 3 diferentes condições: descalças, com tênis e com calçado de salto de 10 cm. A atividade EMG do vasto medial oblíquo (VMO), vasto lateral (VL) e reto femoral (RF) foi registrada durante a execução das tarefas por meio de eletrodos de superfície simples diferencial conectados ao eletromiógrafo. Para comparação entre grupos e tarefas, foi utilizado o teste ANOVA com medidas repetidas e o post hoc do teste de Tukey (p<0,05). Os resultados demonstraram maior atividade EMG do músculo VMO, no grupo Controle, durante as tarefas de levantar e sentar utilizando o salto alto. No grupo SDFP, foi observado aumento da atividade EMG do VL na tarefa de levantar do banco e diminuição da razão VMO:VL com o uso do salto alto. Os resultados mostraram que o uso do salto alto pode provocar um aumento da atividade do VL em relação ao VMO em mulheres com SDFP, fato esse que pode colaborar para o mau alinhamento patelar e agravamento da SDFP. Portanto, os resultados sugerem que esse tipo de calçado deve ser evitado por mulheres com SDFP.