Muscle synergies analysis shows altered neural strategies in women with patellofemoral pain during walking.

Several studies suggest that the central nervous system coordinates muscle activation by modulating neural commands directed to groups of muscles combined to form muscle synergies. Individuals with patellofemoral pain (PFP) move differently from asymptomatic individuals. Understanding the neural strategies involved in the execution of tasks such as walking can help comprehend how the movement is planned and better understand this clinical condition. The objective of this study was to compare muscle synergies between women with and without PFP during walking. Eleven women with PFP and thirteen asymptomatic women were assessed using three-dimensional kinematics and electromyography (EMG) while walking at self-selected speed. Kinematics of the trunk, pelvis and lower limbs were analyzed through the Movement Deviation Profile. Muscle synergies were extracted from the EMG signals of eight lower limb muscles collected throughout the whole gait cycle. Kinematic differences between the two groups (p<0.001, z-score = 3.06) were more evident during loading response, terminal stance, and pre-swing. PFP group presented a lower number of muscle synergies (p = 0.037), and greater variability accounted for (VAFtotal) when using 3 (p = 0.017), 4 (p = 0.004), and 5 (p = 0.012) synergies to reconstruct all EMG signals. The PFP group also presented higher VAFmuscle for rectus femoris (p = 0.048) and gastrocnemius medialis (p = 0.019) when considering 4 synergies. Our results suggest that women with PFP show lower motor complexity and deficit in muscle coordination to execute gait, indicating that gait in PFP is the result of different neural commands compared to asymptomatic women.

The Movement Deviation Profile Can Differentiate Faller and Non-Faller Older Adults.

BACKGROUND: The World Health Organization considers falls the second leading cause of death by accidental injury worldwide and one of the most frequent complications in older adults during activities of daily living. Several tasks related to fall risk have been individually assessed describing kinematic changes in older adults. The study proposal was to identify which functional task differentiates faller and non-faller older adults using the movement deviation profile (MDP). METHODS: This cross-sectional study recruited 68 older adults aged ≥60 years by convenience sampling. Older adults were divided into 2 groups: with and without a history of falls (34 older adults in each group). The MDP analyzed the 3-dimensional angular kinematics data of tasks (ie, gait, walking turn, stair ascent and descent, sit-to-stand, and stand-to-sit), and the Z score of the mean MDP identified which task presented the greatest difference between fallers and non-fallers. A multivariate analysis with Bonferroni post hoc verified the interaction between groups considering angular kinematic data and the cycle time of the task. Statistical significance was set at 5% (p < .05). RESULTS: Z score of the MDPmean showed an interaction between groups (λ = 0.67, F = 5.085, p < .0001). Fallers differed significantly from non-fallers in all tasks and the greatest difference was in stair descent (Z score = 0.89). The time to complete each task was not different between groups. CONCLUSIONS: The MDP distinguished older adult fallers from non-fallers. The stair descent task should be highlighted because it presented the greatest difference between groups.

Effects of Foot Orthoses on Pain and the Prevention of Lower Limb Injuries in Runners: Systematic Review and Meta-Analysis.

CONTEXT: A variety of approaches have been proposed to prevent lower limb injuries in runners. However, the evidence for the effectiveness of interventions to reduce lower limb pain and injury after intensive running is very weak. OBJECTIVE: The authors performed a systematic review to investigate the effects of foot orthoses on pain and the prevention of lower limb injuries in runners. EVIDENCE ACQUISITION: The authors searched the MEDLINE/PubMed, Physiotherapy Evidence Database, Scielo, and Cochrane Central (from inception to February 2022) databases for randomized controlled trials that evaluated the effects of foot orthoses in runners. The authors then calculated mean differences and 95% confidence intervals from these trials. Heterogeneity was assessed using the I2 test. Furthermore, the authors compared the criteria between runners with foot orthoses and ones with no intervention (control group). EVIDENCE SYNTHESIS: Twelve studies (5321 runners) met our review criteria. The control and the foot orthoses group sustained 721 (37%) and 238 (24%) injuries, respectively. Compared with the control group, the use of foot orthoses resulted in a significant reduction in lower limb injury risk (risk ratio = 0.6; 95% confidence interval, 0.5-0.7; P = .00001, I2 = 54%; 7 studies, N = 2983: moderate-quality evidence). Moreover, the foot orthoses group corresponded to a 40% reduction in the risk of developing lower limb injuries. CONCLUSIONS: The use of foot orthoses may help reduce the incidence of lower limb injuries and pain in runners.

Is there a correlation between isometric muscle strength and the kinematics of the pelvis, hip and knee during functional tasks in women with patellofemoral pain?

OBJECTIVES: To evaluate the correlation between isometric muscle strength of the hip abductors (HABD) and lateral rotators (HLR) with the range of motion (ROM) of the pelvis/hip in the frontal/transverse planes, respectively, and between the strength of the knee extensors (KExt) with the ROM of the knee in the sagittal plane during seven tasks. DESIGN: Cross-sectional study. SETTING: Laboratory. PARTICIPANTS: Thirty-five women with patellofemoral pain. MAIN OUTCOME MEASURES: Maximum isometric muscle strength of the HABD, HLR, and KExt was measured using a manual dynamometer, and pelvis and lower limbs kinematics were evaluated using 3D optical system during gait, ascending and descending stairs, the forward and lateral step down tests, and the propulsion and landing phases of the single leg hop test (SLHT). RESULTS: A weak correlation was found between KExt strength and knee ROM in the sagittal plane (p = 0.05; r = -0.33) during SLHT landing, and a moderate correlation between HABD strength and ROM of pelvic obliquity (p < 0.01; r = 0.50) during ascending stairs. CONCLUSIONS: The lower strength of KExt has a weak correlation with higher knee flexion during the landing phase of the SLHT, and the lower strength of HABD has a moderate correlation with lower pelvis ROM in the frontal plane when ascending stairs.

Kinematic analysis of the ankle/foot complex mobility of women with PFP during weight bearing functional tests / Análise cinemática da mobilidade do complexo tornozelo/pé de mulheres com DFP durante testes funcionais de descarga de peso

Abstract: Patellofemoral pain (PFP) has been frequently associated with abnormalities in the alignment of the lower limbs and trunk, particularly during weight-bearing activities. In this context, proximal and local factors have been widely discussed. Distal factors could also be involved and need to be investigated in more detail. Our objective was to compare the foot kinematics of the ankle/foot complex in women with pronated feet and patellofemoral pain with the kinematics of asymptomatic women during the execution of anterior and lateral step down tests. Methods: Fifty women were divided into two groups: control (n=16); and patellofemoral pain (n=34). All volunteers were evaluated using three-dimensional motion capture during the forward and lateral step-down tests. For each session, nine repetitions of each clinical test were performed on the most painful limb of the women with PFP and the dominant limb of the women in the control group. The mobility of the ankle/foot complex was measured and the range of motion was calculated for all segments. The two groups were compared using multivariate analysis of variance. Results: Women in the PFP group exhibited less knee flexion and significantly greater mobility of: the hindfoot in relation to the tibia and the laboratory; the forefoot in relation to the tibia; and the forefoot in relation to the hindfoot. Conclusion: Women with PFP exhibited greater mobility of the ankle/foot complex during the anterior and lateral step down tests, when compared with asymptomatic women.

Resumo: Introdução: A dor femoropatelar (DFP) tem sido frequentemente associada a anormalidades no alinhamento dos membros inferiores e tronco, principalmente durante atividades de descarga de peso. Nesse contexto, fatores proximais e locais têm sido amplamente discutidos. Fatores distais também podem estar envolvidos e precisam ser investigados com mais detalhes. Nosso objetivo foi comparar a cinemática do complexo tornozelo/pé em mulheres com pés pronados e dor femoropatelar pormeio de cinemática tridimensional de mulheres assintomáticas durante a execução dos testes step down anterior e lateral. Métodos: Cinquenta mulheres foram divididas em dois grupos: controle (n=16); e dor patelofemoral (n=34). Todos os voluntários foram avaliados usando captura de movimento tridimensional durante os testes step down anterior e lateral. Para cada sessão, foram realizadas nove repetições de cada teste clínico no membro mais doloroso das mulheres com DFP e no membro dominante das mulheres do grupo controle. A mobilidade do complexo tornozelo/pé foi medida e a amplitude de movimento foi calculada para todos os segmentos. Os dois grupos foram comparados por meio de análise multivariada (MANOVA). Resultados: As mulheres do grupo DFP apresentaram menor flexão do joelho e mobilidade significativamente maior de: retropé em relação à tíbia e ao laboratório; do antepé em relação à tíbia; e do antepé em relação ao retropé. Conclusão: Mulheres com DFP apresentaram maior mobilidade do complexo tornozelo/pé durante os testes de step down anterior e lateral, quando comparadas com mulheres assintomáticas.

Three-dimensional kinematic analysis of upper limb movements between individuals with and without subacromial shoulder pain exploring the statistical parametric mapping.

Subacromial shoulder pain (SSP) accounts for 44-65% of all cases of shoulder pain. Kinematic alterations in the upper limbs have been observed in individuals with SSP, although there is no consensus on such alterations in the literature. Therefore, the present study aimed to compare the three-dimensional kinematics of the scapula, trunk, and arm during shoulder flexion-extension and abduction-adduction movements in individuals with SSP and a control group using statistical parametric mapping (SPM). We evaluated 117 participants [61 with SSP and 56 in the control group (CG)]. The three-dimensional kinematic analysis was performed starting from arm extension/adduction (0%), moving to flexion/abduction, and ending returning to extension/adduction, respectively (100%) in both groups. SSP group flexed more their trunk (0-100%, p < 0.001) and rotated scapula internally (0-20%, p < 0.001 and 75-100%, p < 0.001); rotated upwards (17-32%, p < 0.005 and 58-87%, p < 0.003) and posteriorly tilted (28-79%,p < 0.001 and 81-95%,p < 0.006) less than CG group during arm abduction-adduction. Through arm flexion-extension, the SSP group flexed (38-82% p < 0.009) less their trunk, rotated upwards (5-10% p = 0.021) less their scapula, and posteriorly tilted scapula (0-100% p < 0.001) more than CG. Combining conventional variables used to describe motion in individuals with SSP, such as minimum and maximum values, range of motion, and results provided by SPM can furnish a detailed description of the compensations and limitations of the patient, enabling a better understanding of the function of the scapular girdle as well as improvements in the evaluation process and clinical decision making.

Correlation of pain sensitization with muscle strength and angular kinematics in women with patellofemoral pain.

BACKGROUND: Patellofemoral pain has a poor long-term prognosis, which can be explained by a pain sensitization process. The pain sensitization process may be related to the increase of stress in the patellofemoral joint that is already associated with kinematic alterations and weakness in the musculature of the hip and knee. METHODS: Were compared the pressure pain threshold, temporal summation, conditioned pain modulation, angular kinematics, and muscle strength between 26 patellofemoral pain and 24 asymptomatic women and then correlated pain sensitization variables with biomechanical variables in pain group. The pressure pain threshold was determined on seven points of the knee, tibialis anterior muscle, and elbow. Ten consecutive stimuli were performed for temporal summation, and cold water was used as the conditioning stimulus for conditioned pain modulation. The strength of hip and knee muscles was determined using a manual dynamometer. Three-dimensional kinematics were evaluated during the lateral step down, considering peak and excursion values of the movement and the Movement Deviation Profile. FINDINGS: The pressure pain threshold of the elbow (2.13 [1.84-2.41] vs. 1.63 [1.25-2] kg/cm2), all sites of the knee were lower, as well as the Movement Deviation Profile was higher (9.33 [9.20-9.46] vs. 12.43 [12.1-12.75]) in the pain group. No difference in temporal summation, conditioned pain modulation, muscle strength and discrete kinematic values were found. No significant correlation was found between the Movement Deviation Profile and pressure pain threshold. INTERPRETATION: Biomechanical factors, pain processing, and modulation in women with patellofemoral pain, when different from asymptomatic individuals, are not necessarily associated.

Women with patellofemoral pain show altered motor coordination during lateral step down.

Patients with patellofemoral pain (PFP) present altered activation of the hip and knee muscles. Electromyography (EMG) analyses in PFP patients are usually performed individually for each muscle. However, several studies suggest that the central nervous system may modulate neural commands directed to groups of co-activated muscles, called muscle synergies. Investigating the synergistic organization in PFP will advance our knowledge of the influence of pain on muscle coordination. This study aimed to compare the motor coordination between women with and without PFP during the lateral step down (LSD). 15 women with PFP and 14 asymptomatic women underwent three-dimensional kinematics and EMG assessment during LSD. The Movement Deviation Profile (MDP) was calculated from kinematic data. Muscle synergies were extracted from EMG data of eight lower limb muscles using a non-negative factorization algorithm. Results revealed differences in MDP and an altered synergistic control between women with PFP and asymptomatic while performing the same motor gesture. Particularly, the variability accounted for (VAF) when using 3 synergies to reconstruct EMGs of the PFP group was higher than in the control group, suggesting reduced complexity of motor control in PFP. Detailed synergy analyses highlighted specific differences between groups in vastii and rectus femoris, which are muscles with a crucial role during the squat phase and the transition to rise phase of the LSD. This study shows the ability of muscle synergies analysis to reveal impaired motor coordination in PFP patients, and has the potential to be explored as a complementary tool to current clinical assessment techniques.

Do hip strength, flexibility and running biomechanics predict dynamic valgus in female recreational runners?

BACKGOUND: Dynamic valgus has been the focus of many studies to identify its association to an increased risk of running-related injuries. However, it is not known which physical and biomechanical variables are associated with this movement dysfunction. RESEARCH QUESTION: This study aimed to test the correlation between strength, flexibility and biomechanical variables and dynamic valgus in female runners. METHODS: Twenty-nine healthy females ran on a treadmill at 2.92 m/s and performed strength, range of motion and endurance tests. Pelvic, hip and ankle kinematics were measured with a 3D motion analysis system. Six multiple linear regression models were used to identify the ability of physical and biomechanical variables to predict excursion and peak of contralateral pelvic drop, hip adduction and internal rotation. RESULTS: Contralateral pelvic drop and hip adduction were positively correlated to ankle eversion and step cadence. Hip internal rotation had a negative correlation with ankle eversion. Despite significance, predictor variables explained less than 30% of dynamic valgus variance during running. No interest variable had significant correlation with the hip strength and hip and ankle passive range of motion. SIGNIFICANCE: The results showed that distal joint kinematics and spatiotemporal variables should be considered during biomechanical running analysis to identify their possible relationship with joint overload caused by dynamic valgus. Caution should be taken when linking hip disorders during running to posterolateral hip strength and stiffness, core endurance, and ankle dorsiflexion range of motion since no correlation occurred amongstthese variables in this sample of female runners.

Kinematics and muscle forces in women with patellofemoral pain during the propulsion phase of the single leg triple hop test.

BACKGROUND: Approximately 25% of orthopedic knee conditions are related to patellofemoral pain (PFP), with young women being the most affected. It is thought that this condition is associated with modifications in the kinematics and muscle control patterns of the lower limb during weight-bearing support activities, which increases femur movement under the patella. OBJECTIVES: To compare kinematics and muscle induced acceleration patterns between PFP subjects and healthy controls during the preparation phase of the single leg triple hop test. STUDY DESIGN: Biomechanical analysis was performed using OpenSim. Ten physically active women (23.2 ±â€¯4 years, 59.3 ±â€¯5.8 kg, and 1.63 ±â€¯0.06 m) with no history of lower limb injury (CG) and 11 volunteers (23.5 ±â€¯2 years, 55.4 ±â€¯4.9 kg, and 1.66 ±â€¯0.04 m) with PFP (PFPG) were recruited. The participants performed a series of single leg triple hop tests while the ground reaction forces and kinematic data were recorded. RESULTS: Vector field statistical analysis indicated increased lumbar extension, anterior pelvic tilt, contralateral pelvic drop, and lower induced accelerations from the core and hip muscles in PFPG. CONCLUSION: PFP volunteers presented with alterations in lumbar muscle control associated with a possible compensatory pelvic strategy to minimize knee extensor moment.

Are we supererestimating gait assessments of patients with idiopathic normal-pressure hydrocephalus?

INTRODUCTION: Idiopathic normal pressure hydrocephalus (iNPH) is a syndrome characterized by a triad composed of cognitive alteration, urinary incontinence, and gait impairment associated with ventricular enlargement and normal cerebrospinal fluid pressure. Gait impairment is among the earliest symptoms; however, the reliability of the evaluation is not well-established and no consensus has been reaching regarding variables that should be analyzed and which parameters should be considered to accurately assess post-intervention improvement. RESEARCH QUESTION: Are the degree of repeatability, standard error of measurement, and minimum detectable change considered to detect changes in gait variables in iNPH patients? METHODS: A total of 84 iNPH patients with a mean age of 77.1 (±6.4) years were analyzed. Gait deviation index (GDI), speed, cadence, cycle time, stride length, single support, and first and second double support were chosen as the variables to be analyzed. Statistical analysis was performed by an independent evaluator, with gait repeatability assessed by the intraclass correlation coefficient (ICC) and the standard error of measure (SEM). RESULTS: ICC values were 0.76-0.85 with excellent repeatability, while SEM demonstrated that the variables with best repeatability were the GDI (mean, 4.94; 95% confidence interval (CI), 4.63-5.43), representing a 7.65% mean relative error of the measurement (mean, 0.05 m; 95% CI, 0.05-0.06), and stride length (mean 0.05 m; 95% CI, 0.05-0.06), with a 7.69% mean relative error. SIGNIFICANCE: We concluded that GDI and stride length were the variables with the best repeatability and lower variability in the gait of iNPH patients.

Does the examiner's experience matter in evaluation of the kinematics of the upper limb?

This study aimed to evaluate test and retest reliability according to examiner experience with the three-dimensional kinematics of the trunk, scapula, and arm segments during flexion and unilateral abduction of the arm. Ten men and 10 women (mean age, 25.1 [1.1] years) participated in this study. Each volunteer participated in six test sessions, four on the first day (two for each examiner) and two on the second day (one for each examiner). A 48-h interval was given between test days. The assessments were made by one examiner with movement analysis experience and a second examiner without experience. For each session (intra-day), the volunteers performed five repetitions of unilateral arm flexions and abductions using their dominant arms. After 1 h, the data were re-collected and all markers were replaced. Data from the trunk, scapula, and arm were analysed at 30°, 60°, 90°, and 120° of arm flexion and abduction using intraclass coefficient correlation, standard error of the measurement, and analysis of variance. The results did not differ between the experienced and inexperienced examiners except for trunk axial rotation at all studied angles and for arm rotation at 120° of abduction. The examiner previously trained in movement analysis marker placement demonstrated the same intra-tester reliability as the inexperienced tester when marker placement accuracy was the variable of interest.

Biofeedback for pelvic floor muscle training in women with stress urinary incontinence: a systematic review with meta-analysis.

BACKGROUND: Several clinical effects have been attributed to the use of biofeedback (BF) as an adjuvant in the treatment of women with stress urinary incontinence (SUI). OBJECTIVES: To determine whether BF is more effective than other interventions for women with SUI in terms of quantification of urine leakage, episodes of urinary loss, quality of life and muscle strength. DATA SOURCES: Science Direct, Embase, MEDLINE, Pedro, SciELO, CINAHL and LILACS from January 2000 to February 2017. STUDY SELECTION: Randomised controlled trials (RCTs) addressing the effects of pelvic muscle floor training (PFMT) with BF for the conservative treatment of women with SUI. DATA EXTRACTION AND DATA SYNTHESIS: Two independent assessors extracted data from articles. The risk of bias for individual studies was assessed using the Jadad scale and Physiotherapy Evidence Database (PEDro) scale. Mean differences (MD) and 95% confidence intervals were calculated and combined in meta-analyses. RESULTS: In total, 1194 studies were retrieved and 11 were included in this review. Only two RCTs demonstrated a low risk of bias according to the PEDro scale. The results demonstrated that PFMT with BF was no better than alternative interventions in terms of muscle strength measured using a perineometer. LIMITATIONS: Low methodological quality of studies, heterogeneity of outcomes, and differences in implementation of intervention protocols and BF modalities. CONCLUSIONS: PFMT with BF does not offer therapeutic benefits over alternative interventions (no training, PFMT alone and vaginal electrical stimulation) for the treatment of female SUI. SYSTEMATIC REVIEW REGISTRATION NUMBER PROSPERO: CRD42017060780.

Age-Related Changes in Postural Control in Physically Inactive Older Women.

BACKGROUND AND PURPOSE: The maintenance of postural control is influenced by the complexity of a given task. Tasks that require greater attention and cognitive involvement increase the risk of falls among older adults. The aim of the present study was to evaluate the adaptation of the postural control system to different levels of task complexity in physically inactive young and older women. METHODS: A cross-sectional study was conducted with adult women classified as physically inactive based on the results of the International Physical Activity Questionnaire. The participants were 27 young (20-30 years of age) and 27 older (60-80 years of age) women. Sway velocity of the center of pressure in the anterior-posterior and medial-lateral directions was calculated using a force plate under 6 conditions: standing directly on the force plate or on a foam placed over the force plate, eyes open or closed, and dual-task complexity with and without the foam. RESULTS AND DISCUSSION: A 2-way analysis of variance revealed that sway velocity increased in both groups when the task conditions were altered. The older women exhibited significantly greater sway velocity compared with the young women on all tasks. However, the patterns of postural control adaptation to the different levels of complexity were similar among all participants. CONCLUSIONS: In this study, the adaption of the postural control system to different levels of task complexity did not differ between physically inactive young and physically inactive older women. However, the physically inactive older women exhibited greater sway velocity compared with the young women.

Descending stairs: Good or bad task to discriminate women with patellofemoral pain?

BACKGROUND: There is no consensus on kinematics alterations during descending stairs in females with patellofemoral pain (PFP). In addition, there are no studies that have evaluated the three dimensional kinematics of the trunk, pelvis, hip, knee, and ankle using a multi-segmental model of the foot simultaneously during this task in patients with PFP and evaluated the subphases of stair descent. The objectives of this study were to compare the three dimensional kinematics of the trunk, pelvis, and lower limbs during different subphases of stair descent and identify the discriminatory capacity of the kinematic variables among women with PFP and healthy women. METHODS: In this cross-sectional study, thirty-four women with PFP and thirty-four pain free women between 18 and 35 years-old were submitted to three-dimensional kinematic evaluation during stair descent. RESULTS: It was observed that kinematic differences between the groups occurred in the first double support phase of the stair descent, with the variables of internal rotation of the hindfoot in relation to the tibia in the initial contact (2.1°; sensitivity = 68.6%, specificity = 61.8%) and contralateral pelvic drop in load response (1.3°, sensitivity = 65.7%, specificity = 63.7%) presenting the best ability to discriminate women with and without PFP. CONCLUSION: Our results suggest that kinematic changes during stair descent should be used with caution during the evaluation and decision-making process in women with PFP.

Female PFP patients present alterations in eccentric muscle activity but not the temporal order of activation of the vastus lateralis muscle during the single leg triple hop test.

This study aimed to compare the concentric and eccentric activity and the temporal order of peak activity of the hip and knee muscles between women with patellofemoral pain (PFP) and healthy women during the single leg triple hop test (SLTHT). Electromyographic (EMG) and Kinematic data were collected from 14 healthy women (CG) and 14 women diagnosed with PFP (PFG) during a single session of the single leg triple hop test. Integral surface electromyography (iEMG) data of the hip and knee muscles in eccentric and concentric phases and the length of time that each muscle needed to reach the maximal peak of muscle activity were calculated. The iEMG in the eccentric phase was significantly higher (p < 0.05) than the concentric phase, for the gluteus maximus and gluteus medius muscles (CG and PFG) and for the vastus lateralis muscle (PFG). The vastus lateralis muscle was the first muscle to reach the highest peak of activity in the PFG, and the third to reach this peak in the CG. In the present study, the activity of the vastus lateralis muscle during the eccentric phase of the jump was greater than concentric phase, as a temporal anticipation of its peak in activity among women with PFP.

The effect of a six-week osteopathic visceral manipulation in patients with non-specific chronic low back pain and functional constipation: study protocol for a randomized controlled trial.

BACKGROUND: The aim of the proposed study is to analyze the effect of a six-week osteopathic visceral manipulation (OVM) program on the flexion-relaxation phenomenon in individuals with non-specific chronic low back pain (LBP) and functional constipation. METHODS/DESIGN: An assessor-blinded, two-arm, randomized, placebo-controlled trial will be conducted. The sample will comprise 76 individuals with non-specific chronic LBP who have functional intestinal constipation, aged 18-65 years. The participants will be randomly allocated to two groups: (1) OVM and (2) sham OVM (SOVM). Evaluations will involve an interview, the Oswestry Disability Index, Fear-Avoidance Beliefs Questionnaire, functional constipation according to Rome III criteria, Biering-Sorensen test to normalize electromyographic (EMG) data, T12-L1 paraspinal level of the EMG signal during the flexion-relaxation phenomenon, 11-point numeric pain rating scale and fingertip-to-floor test. OVM and SOVM will be performed once per week for six weeks. Group 1 will receive OVM for 15 min and Group 2 will receive a sham visceral technique. Evaluations will be performed before and after the first session, after six weeks of treatment, and three months after randomization (follow-up). The findings will be analyzed statistically considering a 5% significance level (p ≤ 0.05). The limitation of the study is that the therapist will not be blinded. DISCUSSION: This will be the first trial to analyze the clinical response and electromyographic signals during the flexion-relaxation phenomenon after OVM. TRIAL REGISTRATION: Brazilian Clinical Trial Registry, RBR-7sx8j3 . Registered on 26 October 2017.

Predicting muscle forces during the propulsion phase of single leg triple hop test.

Functional biomechanical tests allow the assessment of musculoskeletal system impairments in a simple way. Muscle force synergies associated with movement can provide additional information for diagnosis. However, such forces cannot be directly measured noninvasively. This study aims to estimate muscle activations and forces exerted during the preparation phase of the single leg triple hop test. Two different approaches were tested: static optimization (SO) and computed muscle control (CMC). As an indirect validation, model-estimated muscle activations were compared with surface electromyography (EMG) of selected hip and thigh muscles. Ten physically healthy active women performed a series of jumps, and ground reaction forces, kinematics and EMG data were recorded. An existing OpenSim model with 92 musculotendon actuators was used to estimate muscle forces. Reflective markers data were processed using the OpenSim Inverse Kinematics tool. Residual Reduction Algorithm (RRA) was applied recursively before running the SO and CMC. For both, the same adjusted kinematics were used as inputs. Both approaches presented similar residuals amplitudes. SO showed a closer agreement between the estimated activations and the EMGs of some muscles. Due to inherent EMG methodological limitations, the superiority of SO in relation to CMC can be only hypothesized. It should be confirmed by conducting further studies comparing joint contact forces. The workflow presented in this study can be used to estimate muscle forces during the preparation phase of the single leg triple hop test and allows investigating muscle activation and coordination.

Do hip muscle weakness and dynamic knee valgus matter for the clinical evaluation and decision-making process in patients with patellofemoral pain?

BACKGROUND: Patellofemoral pain is a very common musculoskeletal condition. In the last years, evidence regarding this disease increased exponentially. Although widely investigated, this problem still frustrates patients and clinicians for having an unfavorable prognosis. Some gaps still exist in the understanding and managing of patellofemoral pain. Numerous cross-sectional association studies show an association between gluteus muscular strength and dynamic knee valgus in patients with patellofemoral pain. In spite of this biological plausibility, many evidences challenge the direct relationship between these factors. Recent studies have concluded that women with patellofemoral pain show muscular weakness of the hip based on the cross-sectional studies, however prospective studies indicate that hip weakness cannot be considered a risk for development of patellofemoral pain. In addition, some clinical trials have demonstrated that strength training of the gluteal muscles promotes significant improvement in symptoms but not alter the kinematics of the patients with patellofemoral pain. These findings cast doubt on whether the cause of this condition is really being treated, whether all individuals suffering from patellofemoral pain present dynamic knee valgus or if this is a disturbance present in only a subgroup of patients and whether the strengthening of the hip musculature is an option to consider for prevention of patellofemoral pain. CONCLUSION: Certainly, more studies should be conducted to clarify the influence of mechanical patterns on this condition, but with the existing evidence so far, the importance given to these issues in the evaluation and clinical decision on treatment of these patients seems questionable. Therefore, this masterclass explores the understanding about patellofemoral pain, highlighting mainly the importance of muscular strength and dynamic knee valgus, as well as other possible factors that must be consider during the evaluation and the decision making in these patients.