Marcelo Camargo Saad

Analysis of the center of pressure displacement, ground reaction force and muscular activity during step exercises.

Anterior Knee Pain (AKP) is considered as one of the most common, yet misunderstood, knee pathologies. The aim of this study was to evaluate the displacement area of the center of pressure, Ground Reaction Force (GRF), and the electromyography activity of the hip and the quadriceps muscles in healthy and AKP individuals during the step-up and step-down exercises. Both groups (Control group and AKP group) were composed of 15 volunteers submitted to the exercises on a force plate. The AKP group presented greater displacement area of the center of pressure for all the situations evaluated than the Control group (p<0.05), as well as a lesser magnitude of the GRF during the step-down exercise. The AKP group presented lower electromyography activity than the Control group in all situations evaluated. AKP individuals do not have muscle imbalances; they present a lower electromyography activity of the stabilizing muscles of the patella and hip and show greater instability in activities such as step up and down compared to normal subjects.

Analysis of patellar stabilizers muscles and patellar kinematics in anterior knee pain subjects.

Patella stabilizer muscle response and patellar kinematics were evaluated in 19 women with anterior knee pain (AKP) and 20 healthy women during maximum voluntary isometric contraction (MVIC) with the knee positioned at 15°, 30° and 45° flexion during open (OKC) and closed (CKC) kinetic chain exercises. Patellar kinematics was evaluated through patellar tilt and displacement, and the electrical activity of patellar stabilizers through the root mean square normalized during MVIC and OKC with the knee at 90° flexion. Data revealed that the vastus medialis oblique muscle (VMO) was more active in the control group compared to the AKP group during OKC exercises with the knee at 45° flexion. However, no difference in the patellar kinematics was observed between these groups; nevertheless, the correlation between these parameters also showed, with the knee at 45° flexion, that lateral patellar tilt increase was associated with a reduction in the activity of lateral patellar stabilizers in the control group and with an increase in the VMO activity in the AKP group. In conclusion, electrical activity is an important factor in evaluating AKP and in AKP treatment evolution.

The Effect of a Patellar Bandage on the Postural Control of Individuals with Patellofemoral Pain Syndrome

A patellar bandage is often used by individuals with patellofemoral pain syndrome (PPS) to reduce pain and the additional sensorial input improves proprioception of the knee joint. The aim of this work was to assess the effect of a patellar bandage on the postural control of individuals with and without PPS. [Subjects and Methods] An analysis was performed of variables of center of pressure (CoP) as recorded by a force plate. Information about the forces and moments in three directions was used to obtain the CoP. Thirty women participated in this study: 15 with PPS and 15 without PPS. All subjects performed 3 trials in a unipodal stance with and without a patellar bandage. The force plate data were used to calculate the following variables: CoP sway area, CoP displacement frequency, and CoP mean velocity for the anteroposterior (AP) and mediolateral (ML) directions. A the linear mixed effects model was used for statistical analysis. [Results] Postural sway was significantly reduced in individuals with PPS when a patellar bandage was applied. [Conclusion] Additional sensory input from a patellar bandage increase proprioceptive feedback and this could be related to the improvement in postural control of PPS subjects.

Quantitative MRI of Vastus Medialis, Vastus Lateralis and Gluteus Medius Muscle Workload after Squat Exercise: Comparison Between Squatting with Hip Adduction and Hip Abduction

Quantitative MRI of Vastus Medialis, Vastus Lateralis and Gluteus Medius Muscle Workload after Squat Exercise: Comparison Between Squatting with Hip Adduction and Hip Abduction The aim of the present study was to evaluate the use MRI to quantify the workload of gluteus medius (GM), vastus medialis (VM) and vastus lateralis (VL) muscles in different types of squat exercises. Fourteen female volunteers were evaluated, average age of 22 ± 2 years, sedentary, without clinical symptoms, and without history of previous lower limb injuries. Quantitative MRI was used to analyze VM, VL and GM muscles before and after squat exercise, squat associated with isometric hip adduction and squat associated with isometric hip abduction. Multi echo images were acquired to calculate the transversal relaxation times (T2) before and after exercise. Mixed Effects Model statistical analysis was used to compare images before and after the exercise (ΔT2) to normalize the variability between subjects. Imaging post processing was performed in Matlab software. GM muscle was the least active during the squat associated with isometric hip adduction and VM the least active during the squat associated with isometric hip abduction, while VL was the most active during squat associated with isometric hip adduction. Our data suggests that isometric hip adduction during the squat does not increase the workload of VM, but decreases the GM muscle workload. Squat associated with isometric hip abduction does not increase VL workload.

Contribuição da avaliação dos sinais clínicos em pacientes com síndrome da dor patelofemural

OBJECTIVE: As patellofemoral pain syndrome (PFPS) is a common disorder characterized by multifactorial etiology and whose the most prevalent symptom is a diffuse pain, usually located on the retropatellar region, however, it also shows signs and symptoms that can be related as excessive subtalar pronation, external tibial torsion, patellar displacement alterations, painful range of motion of the knee, pain in the patellar borders, muscular tightness and changes in quadriceps angle (Q Angle), the objective of this work was to determine the frequency of these signs and symptoms associated to a previous knee pain questionnaire. METHODS: Thirty-nine sedentary female volunteers had been evaluated, divided in two groups, PFPS (19) and Control (20). These subjects were evaluated for signs and symptoms described above, in addition to pain assessment by questionnaire. RESULTS: The results demonstrated a high frequency of pain in six of the thirteen questions in relation to the control group. CONCLUSION: According to these findings, we conclude that the functional evaluation of individuals with PFPS should consist of a previous knee pain questionnaire and an evaluation of the characteristic signs and symptoms for examination of the entire lower limb during static and functional situations. Level of Evidence II, Diagnostic Studies.OBJETIVO: Como a sindrome da dor patelofemoral (SDPF) e uma desordem comum, caracterizada por etiologia multifatorial e o mais prevalente sintoma na SDPF e uma dor difusa e usualmente localizada na regiao retropatelar, entretanto, com sinais e sintomas que podem estar relacionados como pronacao subtalar excessiva, torsao tibial externa, alteracoes no deslocamento patelar, amplitude de movimento do joelho dolorosa, dor nas bordas patelares, tensao muscular e alteracoes no ângulo quadricipital (ângulo Q), o objetivo deste trabalho foi verificar a frequencia destes sinais e sintomas associados a um questionario de dor anterior no joelho. METODOS: Trinta e nove voluntarias sedentarias foram avaliadas, divididas em dois grupos, SDPF (19) e controle (20). Estas voluntarias foram avaliadas quanto aos sinais e sintomas supracitados alem da avaliacao da dor por meio de questionario. RESULTADOS: Os resultados demonstraram uma frequencia elevada de relatos dolorosos em seis de treze questoes, em relacao ao grupo controle. CONCLUSAO: De acordo com estes achados, concluimos que a avaliacao funcional de individuos com SDFP deve ser constituida de um questionario de dor anterior no joelho e uma avaliacao das caracteristicas de sinais e sintomas para exame de todo o membro inferior estatico e durante situacoes funcionais. Nivel de Evidencia II, Estudos Diagnosticos.

Is hip strengthening the best treatment option for females with patellofemoral pain? A randomized controlled trial of three different types of exercises

OBJECTIVE To evaluate the effect of three types of exercise intervention in patients with patellofemoral pain and to verify the contributions of each intervention to pain control, function, and lower extremity kinematics. METHODS A randomized controlled, single-blinded trial was conducted. Forty women with patellofemoral pain were randomly allocated into four groups: hip exercises, quadriceps exercises, stretching exercises and a control group (no intervention). Pain (using a visual analog scale), function (using the Anterior Knee Pain Scale), hip and quadriceps strength (using a handheld isometric dynamometer) and measuring lower limb kinematics during step up and down activities were evaluated at baseline and 8 weeks post intervention. RESULTS All treatment groups showed significant improvements on pain and Anterior Knee Pain Scale after intervention with no statistically significant differences between groups except when compared to the control group. Only hip and quadriceps groups demonstrated improvements in muscle strength and knee valgus angle during the step activities. CONCLUSION Hip strengthening exercises were not more effective for pain relief and function compared to quadriceps or stretching exercises in females with patellofemoral pain. Only hip and quadriceps groups were able to decrease the incidence of dynamic valgus during step-down activity. This study was approved by Brazilian Clinical Trials Registry registration number: RBR-6tc7mj (http://www.ensaiosclinicos.gov.br/rg/RBR-6tc7mj/).

Preseason intrinsic risk factors—associated odds estimate the exposure to proximal lower limb injury throughout the season among professional football players

Background/aim Football players frequently face the occurrence of non-contact musculoskeletal injuries. The purpose of the study was to verify whether the evaluation of combined risk factors could produce a score system to determine the probability of injury in football players during the Brazilian football season. Methods Sixty-two male professional soccer players recruited from the first and second division soccer teams, with ages between 18 and 36 years. Functional performance evaluations were carried out at the beginning of the preseason which included strength and jumping tests, history of injuries and characteristics of athletes. Results and conclusions The results were grouped and a score/monogram was constructed.

Cardiac and Musculoskeletal Responses to the Effects of Passive and Active Tilt Test in Healthy Subjects

Background Maintenance of orthostatism requires the interaction of autonomic and muscle responses for an efficient postural control, to minimize body motion and facilitate venous return in a common type of syncope called neurocardiogenic syncope (NCS). Muscle activity in standing position may be registered by surface electromyography, and body sway confirmed by displacement of the center of pressure (COP) on a force platform. These peripheral variables reflect the role of muscles in the maintenance of orthostatism during the active tilt test, which, compared with muscle activity during the passive test (head-up tilt test), enables the analyses of electromyographic activity of these muscles that may anticipate the clinical effects of CNS during these tests. Objective to evaluate and compare the effects of a standardized protocol of active and passive tests for CNS diagnosis associated with the effects of Valsalva maneuver (VM). Methods twenty-thee clinically stable female volunteers were recruited to undergo both tests. EMG electrodes were placed on muscles involved in postural maintenance. During the active test, subjects stood on a force platform. In addition to electromyography and the platform, heart rate was recorded during all tests. Three VMs were performed during the tests. Results progressive peripheral changes were observed along both tests, more evidently during the active test. Conclusion the active test detected changes in muscle and cardiovascular responses, which were exacerbated by the VM.