Neural control of gait in people with haemophilic arthropathy

La hemofilia es un trastorno hemorrágico causado por una deficiencia de los factores VIII o IX de la coagulación. Las personas con hemofilia grave pueden tener hemorragias espontáneas o hemorragias en respuesta a traumatismos menores; la mayoría de los eventos ocurren en las articulaciones y los músculos. La manifestación clínica más frecuente es la artropatía hemofílica, que resulta del sangrado intraarticular repetitivo y de la membrana sinovial inflamada, lo que puede resultar en dolor crónico y deterioro articular. El objetivo general de mi tesis fue investigar el control neural de la marcha en personas con artropatía hemofílica (PCAH). La hipótesis de mi tesis fue que control neural de la marcha se ve afectado en PCAH, y los cambios en el control neural de la marcha están asociados con el daño articular y la cronicidad de la restricción articular. Se seleccionó la marcha, ya que las rodillas y los tobillos son las articulaciones que más se afectan en adultos PCAH. El núcleo de mi tesis fue investigar el control neural mediante el estudio de patrones de actividad de electromiografía (EMG) de músculos individuales y/o sinergias musculares, así como su interacción con la cinemática articular y evaluaciones clínicas. En el capítulo 1, ofrezco una perspectiva general sobre el impacto de la hemofilia en el sistema musculoesquelético, las lagunas actuales en el conocimiento sobre el control neural de la marcha en la artropatía hemofílica y cómo evaluar el control neural de la marcha. En los Capítulos 2 y 4, a través de las evaluaciones de los patrones de activación muscular de músculos individuales, la coordinación entre pares de músculos antagonistas y el análisis de sinergia muscular, confirmamos la hipótesis de que el control neural de la marcha se ve afectado en PCAH. En los capítulos 3 y 5, confirmamos que el control neural alterado de la marcha en PCAH está asociado con la gravedad del daño articular y la cronicidad de la restricción articular. En el capítulo 6, discutimos los resultados de los capítulos centrados en las perspectivas clínicas y fisiológicas del control neural alterado de la marcha en PCAH. Además, discutimos cómo la evaluación del control neuronal a través del índice dynamic motor control index during walking (Walk-DMC) puede ser una alternativa para monitorear el deterioro motor en PCAH. Con base en nuestros resultados, también discutimos cómo mejorar los resultados de la fisioterapia y las intervenciones quirúrgicas que tienen como objetivo mejorar la locomoción en PCAH. Mi tesis contribuye a comprender las consecuencias de la artropatía hemofílica, en especial en la neuromecánica de la marcha. Los hallazgos de mi tesis indican que el control neural de la marcha se ve afectado en PCAH, y los cambios en el control neural de la marcha están asociados con el daño articular, el dolor y cronicidad de la restricción articular. Desde una perspectiva científica, los cambios en el control neural de la marcha en PCAH implican patrones de actividad alterados de los músculos del tren inferior y una reorganización modular de la marcha. Desde una perspectiva clínica, mi tesis brinda una nueva mirada sobre cómo monitorear la progresión de la enfermedad en PCAH utilizando el índice Walk-DMC, brindando nuevas perspectivas para mejorar las intervenciones terapéuticas que apuntan a recuperar la marcha en PCAH.Haemophilia is a bleeding disorder caused by a deficiency of coagulation factors VIII or factor IX. People with severe haemophilia may have spontaneous bleeding events or bleeding in response to minor trauma; most of the events occur in the joints and muscles. The most frequent clinical manifestation is haemophilic arthropathy, which results from repetitive intraarticular bleeding and inflamed synovial membrane, which may result in chronic pain and joint impairment. The overall aim of my thesis was to investigate the neural control of gait in people with haemophilic arthropathy (PWHA). I hypothesized that neural gait control is affected in PWHA, and the changes in neural control of gait are associated with joint damage and chronicity of the joint constraint. Gait was selected because the knees and ankles are the most prevalent affected joints in adults PWHA. The core of my thesis is investigating neural control by studying electromyography (EMG) activity patterns of single muscles and/or muscle synergies, as well as their interaction with joint kinematics and clinical outcomes. In chapter 1, I provide a general perspective about the impact of haemophilia on the musculoskeletal system, the current gaps in knowledge in the neural control of gait in haemophilic arthropathy, and how to assess the neural control of gait. In Chapters 2 and 4, through the assessments of muscle activation patterns of single muscles, coordination between antagonistic muscle pairs, and muscle synergy analysis, we confirmed the hypothesis that the neural control of gait is affected in PWHA. In chapters 3 and 5, we confirm that the altered neural control of gait in PWHA is associated with the severity of joint damage and chronicity of joint constraint. In chapter 6, we discussed the results of chapters focused on clinical and physiological perspectives of the altered neural control of gait in PWHA. In addition, we discuss how the evaluation of neural control through the Walk-DMC index can be an alternative to monitoring the motor impairment in PWHA. Based on our results, we also discussed on how to improve the outcomes of physical therapy and surgical interventions that aimed to improve the locomotion in PWHA. My thesis contributes to understanding the consequences of haemophilic arthropathy for the neuromechanics of gait. The findings of my thesis indicate that neural control of gait is affected in PWHA, and the changes in the neural control of gait are associated with joint damage, pain and chronicity of the joint constraint. From a scientific perspective, the changes in the neural control of gait in PWHA implicate altered activity patterns of single leg muscles and a modular reorganization of gait. From a clinical perspective, my thesis gives a new perspective on how to monitor disease progression in PWHA using the Walk-DMC index—providing new perspectives to improve the therapeutic interventions that aim to recover gait in PWHA

Individuals with chronic ankle instability show altered regional activation of the peroneus longus muscle during ankle eversion

Individuals with chronic ankle instability (CAI) present muscular weakness and potential changes in the activation of the peroneus longus muscle, which likely explains the high recurrence of ankle sprains in this population. However, there is conflicting evidence regarding the role of the peroneus longus activity in CAI, possibly due to the limited spatial resolution of the surface electromyography (sEMG) methods (i.e., bipolar sEMG). Recent studies employing high‐density sEMG (HD‐sEMG) have shown that the peroneus longus presents differences in regional activation, however, it is unknown whether this regional activation is maintained under pathological conditions such as CAI. This study aimed to compare the myoelectric activity, using HD‐sEMG, of each peroneus longus compartment (anterior and posterior) between individuals with and without CAI. Eighteen healthy individuals (No‐CAI group) and 18 individuals with CAI were recruited. In both groups, the center of mass (COM) and the sEMG amplitude at each compartment were recorded during ankle eversion at different force levels. For the posterior compartment, the sEMG amplitude of CAI group was significantly lower than the No‐CAI group (mean difference = 5.6% RMS; 95% CI = 3.4–7.6; p = 0.0001). In addition, it was observed a significant main effect for group (F1,32 = 9.608; p = 0.0040) with an anterior displacement of COM for the CAI group. These findings suggest that CAI alters the regional distribution of muscle activity of the peroneus longus during ankle eversion. In practice, altered regional activation may impact strengthening programs, prevention, and rehabilitation of CAI

Handgrip strength measurement protocols for all-cause and cause-specific mortality outcomes in more than 3 million participants: A systematic review and meta-regression analysis

Background & aims: Handgrip strength is a strong predictor of the risk of mortality. The objective of this systematic review was to analyse handgrip strength measurement protocols used in all-cause and cause-specific mortality studies. Method: A systematic search of PubMed/MEDLINE, Web of Science and Scopus was conducted from inception to February 2022. Prospective cohort studies with objective measures of handgrip strength were included. Studies had to report at least one all-cause, cancer, or cardiovascular mortality outcome. The quality of the included studies was assessed using the Newcastle Ottawa Scale. Meta-regression was used to quantify the bias associated with handgrip strength values in relation to the use of different measurement protocols. Results: Forty-eight studies with a total of 3,135,473 participants (49.6% women) were included. Half of the studies controlled body position, 39.6% arm position, 33.3% elbow position, 12.5% wrist position, 13% handgrip duration, 23% hand-adjustment to dynamometer and 12.5% verbal encouragement. The number of measurements, the laterality of the hand tested, and the estimation method of the handgrip strength value varied considerably between the study protocols. The spline regression model showed a non-linear inverse association between the values of handgrip strength and the number of protocol items controlled. Handgrip strength was higher when the number of measurements per hand or arm position was not controlled. Conversely, handgrip strength was lower when elbow position was not controlled or verbal encouragement were not provided. Conclusion: In general, the protocols used to assess handgrip strength in mortality studies are incomplete and highly heterogeneous. Handgrip strength values were higher when studies controlled fewer handgrip strength measurement protocol variables. There is a need to improve the controlling of handgrip strength measurement protocols and to standardise the method to enhance the accuracy of mortality risk estimates associated with handgrip strength

Does epimuscular myofascial force transmission occur between the human quadriceps muscles in vivo during passive stretching?

This study sought to examine the shear modulus (i.e., an force index) of three quadriceps muscles [i.e., vastus medialis (VM), vastus lateralis (VL), and rectus femoris (RF)] during passive stretching to determine whether epimuscular myofascial force transmission occurs across muscles. Secondly, this study compared the shear modulus between the quadriceps muscles, in both proximal and distal regions. Twelve healthy individuals were assessed during a passive knee flexion maneuver between 0 and 90 of knee flexion with the hip in two positions: flexed (80 ) vs. neutral (0 ). Muscle electrical activity was also assessed during the testing. No differences were observed between the hip testing positions for myoelectric activity (p > 0.43), and for VL and VM shear modulus (p = 0.12–0.98). Similarly, there were no differences between the proximal and distal regions for all muscles (p = 0.42–0.93). RF showed a higher shear modulus with the hip in the neutral position (p = 0.004). With the hip flexed, the VL showed the greatest shear modulus among the tested muscles (p < 0.025); while with the hip in the neutral position, no differences were observed for shear modulus between VL and RF (p = 0.817). These findings suggest that epimuscular myofascial force transmission (at a muscle belly level) does not occur between the quadriceps muscles when passively flexing the knee until 90 . Whether epimuscular myofascial force transmission occurs in the quadriceps muscles bellies with greater muscle stretch (either through knee flexion or hip extension) remains to be examined.info:eu-repo/semantics/publishedVersio

Tolerability and Muscle Activity of Core Muscle Exercises in Chronic Low-back Pain

Most of the studies evaluating core muscle activity during exercises have been conducted with healthy participants. The objective of this study was to compare core muscle activity and tolerability of a variety of dynamic and isometric exercises in patients with nonspecific low back pain (NSLBP). 13 outpatients (average age 52 years; all with standing or walking work in their current or latest job) performed 3 consecutive repetitions at 15-repetition maximum during different exercises in random order. Surface electromyography was recorded for the rectus abdominis; external oblique and lumbar erector spinae. Patients rated tolerability of each exercise on a 5-point scale. The front plank with brace; front plank and modified curl-up can be considered the most effective exercises in activating the rectus abdominis; with a median normalized EMG (nEMG) value of 48% (34-61%), 46% (26-61%) and 50% (28-65%), respectively. The front plank with brace can be considered the most effective exercise in activating the external oblique; with a nEMG of 77% (60-97%). The squat and bird-dog exercises are especially effective in activing the lumbar erector spinae; with nEMG of 40% (24-87%) and 29% (27-46%), respectively. All the exercises were well tolerated; except for the lateral plank that was mostly non-tolerated. In conclusion; the present study provides a variety of dynamic and isometric exercises; where muscle activity values and tolerability can be used as guide to design evidence-based exercise programs for outpatients with NSCLBP

Changes in the ankle muscles co-activation pattern after 5 years following total ankle joint replacement

© 2018 Elsevier Ltd Background: The Hintegra® arthroplasty provides inversion-eversion stability, permits axial rotation, ankle flexion-extension, and improvements of the gait patterns are expected up to 12 months of rehabilitation. However, sensorimotor impairments are observed in ankle flexors/extensors muscles after rehabilitation, with potential negative effects on locomotion. Here we determined the timing and amplitude of co-activation of the tibialis anterior and medial gastrocnemius muscles during gait by assessing non-operated and operated legs of patients with total ankle replacement, 5 years after surgery. Methods: Twenty-nine patients (age: 58 [5.5] years, height: 156.4 [6.5] cm, body mass: 72.9 [6.5] kg, 10 men, and 19 women) that underwent Hintegra® ankle arthroplasty were included. Inclusion criteria included 5 years prosthesis survivorship. The onset and offset of muscle activation (timing), as well as the amplitude of activation, were determined during barefoot walkin

Effectiveness of a Group-Based Progressive Strength Training in Primary Care to Improve the Recurrence of Low Back Pain Exacerbations and Function:A Randomised Trial

Low back pain (LBP) is the leading cause of disability and one of the most common reasons for physician visits in primary care, with a 33% rate of recurrence during the first year. However, the most optimal exercise program in this context remains unknown. The objective was to evaluate the effectiveness of a group-based progressive strength training program in non-specific chronic LBP (CLBP) patients in primary care on pain recurrence and physical function. Eighty-five patients with non-specific CLBP were separated into two groups (Intervention group: completed a progressive strength training program 3 days per week for 8 weeks; Control group: received the usual care). The intervention group showed a recurrence rate of 8.3%, while the control group had a recurrence rate of 33.3% and a shorter time until the first recurrent episode. The intervention group showed increased lumbar extensor strength, left-hand handgrip strength, and reduced the number of pain sites compared with the control group. Results also showed greater odds for reducing LBP intensity and disability in the intervention group. In conclusion, a group-based progressive strength training program is a more effective and efficient alternative than Back-School programs and can easily be carried out in the primary health care context

EMG, Rate of Perceived Exertion, Pain, Tolerability and Possible Adverse Effects of a Knee Extensor Exercise with Progressive Elastic Resistance in Patients with Severe Haemophilia

In people with haemophilia (PWH), elastic band training is considered an optimal option, even though the literature is scarce. The aim was to evaluate normalized electromyographic amplitude (nEMG), rate of perceived exertion (RPE), pain, tolerability, and possible adverse effects during the knee extension exercise using multiple elastic resistance intensities in PWH. During a single session, 14 severe PWH undergoing prophylactic treatment performed knee extensions without resistance and with different intensity levels of elastic resistance. nEMG was measured for the knee extensors and participants rated their RPE, tolerability and pain intensity after each condition. Patients had to report the possible adverse effects after the session. In most of the cases, an nEMG increase is only evidenced after increasing the resistance by two to three levels. Significant associations were found between RPE and the nEMG (&rho; = 0.61), as well as between the elastic resistance level and nEMG (&rho; = 0.69) and RPE (&rho; = 0.71). All conditions were generally tolerated, without increased pain, and no adverse effects were reported. A wide variety of elastic resistance intensities during the knee extension are safe, tolerated, and do not increase knee pain in the majority of severe PWH undergoing prophylactic treatment

Safety, Fear and Neuromuscular Responses after a Resisted Knee Extension Performed to Failure in Patients with Severe Haemophilia

Background: low–moderate intensity strength training to failure increases strength and muscle hypertrophy in healthy people. However, no study assessed the safety and neuromuscular response of training to failure in people with severe haemophilia (PWH). The purpose of the study was to analyse neuromuscular responses, fear of movement, and possible adverse effects in PWH, after knee extensions to failure. Methods: twelve severe PWH in prophylactic treatment performed knee extensions until failure at an intensity of five on the Borg CR10 scale. Normalised values of amplitude (nRMS) and neuromuscular fatigue were determined using surface electromyography for the rectus femoris, vastus medialis, and vastus lateralis. After the exercise, participants were asked about their perceived change in fear of movement, and to report any possible adverse effects. Results: Patients reported no adverse effects or increased fear. The nRMS was maximal for all the muscles before failure, the median frequency decreased, and wavelet index increased during the repetitions. The vastus lateralis demonstrated a higher maximum nRMS threshold and earlier fatigue, albeit with a lower and more progressive overall fatigue. Conclusions: severe PWH with adequate prophylactic treatment can perform knee extensions to task failure using a moderate intensity, without increasing fear of movement, or adverse effects