Muscles In People Research Articles

Gluteus medius and minimus activity during stepping tasks: Comparisons between people with hip osteoarthritis and matched control participants

BackgroundAltered gluteus minimus (GMin) activity has been identified in people with hip osteoarthritis (OA) during gait with some evidence of altered gluteus medius (GMed) activity in patients with advanced OA. It is not known whether these muscles also exhibit altered activity during other functional tasks. Research questionDoes gluteal muscle activity during stepping tasks differ between people with hip OA and healthy older adults? MethodsParticipants included 20 people with unilateral hip OA and 20 age-and sex-matched controls. Muscle activity in the three segments within GMed and two segments of GMin were examined using intramuscular electromyography during step-up, step-down and side-step tasks. ResultsParticipants in the OA group demonstrated reduced muscle activity early in the step-up task and a later time to peak activity in most muscle segments. Greater activity was identified in anterior GMin in people with hip OA during the side-step task. A delay in time to peak activity was identified in most muscle segments in people with OA during the side-step task. SignificanceFor participants with OA, reduced activity in most muscle segments and increased time spent in double limb stance during the step-up task could reflect the decreased strength and pain associated with single limb stance on the affected limb. This study provides further evidence of altered function of the deep gluteal muscles in people with hip OA and highlights the importance of addressing these muscles in rehabilitation.

Sternocleidomastoid muscle activation following inspiratory muscle training in patients with chronic obstructive pulmonary disease: a randomized clinical trial

ABSTRACT This study aims to assess the effect of short-time low frequency inspiratory muscle trainer (Threshold IMT) on inspiratory muscle strength and electromyographic activity of the sternocleidomastoid (SCM) muscle in people with chronic obstructive pulmonary disease (COPD). People with COPD participating in a lung rehabilitation program were allocated to a control or inspiratory muscle training (IMT) group. The control group participated in the usual rehabilitation, whereas the other group received IMT (performed with a load of 50% maximal inspiratory pressure (MIP) adjusted weekly). Both interventions lasted for 2 months. Outcomes included electromyographic analysis of the SCM and MIP. In total, ten participants were allocated to each group. The IMT group presented an increase in absolute (p<0.001) and predicted (p<0.001) values of MIP and also in pre- and post-intervention variation between groups (p=0.003 and p=0.008, respectively). Such differences were not found in the control group. The SCM muscle activity decreased in the IMT post intragroup evaluation (p=0.008). IMT provided a reduction of the electromyographic activity of SCM in COPD patients, also increasing inspiratory muscle strength in the study participants.

Effects of arm cranking exercise on muscle oxygenation between active and inactive muscles in people with spinal cord injury

Objective: We investigated the effects of the incremental arm-cranking exercise (ACE) on tissue oxygen saturation (StO2) between active and inactive muscles, and the relationship between peak oxygen uptake (VO2peak) and changes in the StO2 in inactive muscles. Design: Observational study. Setting: Community-based supervised intervention. Participants: The participants were individuals with motor and sensory complete spinal cord injury (complete SCI; n = 8) and motor complete but sensory incomplete SCI (incomplete SCI; n = 8), and able-bodied (AB) individuals (n = 8) matched for age, height, and body mass index. Intervention: The ACE was performed at a rate increasing by 10 watts min−1 until exhaustion. Outcome Measures: VO2peak, heart rate (HR), and StO2. Results: While VO2peak was similar among the groups, peak HR was significantly higher in both SCI groups than in the AB (P < 0.05). In active muscles (biceps brachii), no differences in the StO2 were observed among the groups (P > 0.05). In inactive muscles (vastus lateralis), the StO2 in the AB and the incomplete SCI began to decrease at approximately 40% of the peak work rate; however, they remained unchanged in the complete SCI. The reductions in StO2 in the AB were significantly greater than in the incomplete SCI. Conclusions: These results suggest that sympathetic vasoconstriction occurred in the incomplete SCI and AB, although it did not occur in the complete SCI, probably due to a reduction in sympathetic nerve activity. Sympathetic vasoconstriction in inactive muscles may not contribute to an individual’s VO2peak regardless of their group.

Reacciones musculares faciales ante imágenes con diferente contenido social. Un índice fisiológico de empatía afectiva

Empathy has two components, the affective and the cognitive component. Affective empathy is the ability to emotionally tune into the emotions that other people experience. Its measurement has been done, traditionally, through self-report measures, however, there are some studies in Latin American population that have used physiological measures of affective empathy. Additionally, it has been hypothesized that people exposed to violent graphic content (e.g., armed conflict) may be desensitized to this type of stimulus. In this context, the objective of the present study was to evaluate the activity of the zygomatic and corrugator muscles to pictures with different social content, in order to establish the validity of these physiological measures as objective indicators of affective empathy. The electromyographic activity of these facial muscles was recorded in 60 subjects (30 with high affective empathy and 30 with low affective empathy), while observing pictures with positive, neutral and negative social content of the International Affective Picture System (IAPS). The results showed that the participants with high affective empathy responded with greater zygomatic muscle activity to positive social pictures ( F 2,96 = 5.93, p = .01, η p 2 = .11) and with greater corrugator muscle activity to negative social pictures ( F 2,96 = 4.85, p = .02, η p 2 = .09), in comparison with participants with low affective empathy. The correlation and regression analyzes show a positive and significant relationship between the scores in the empathic concern scale of the Interpersonal Reactivity Index (IRI) and the activity of the zygomatic muscle to positive social pictures (β = .39, R 2 = .15, t = 3.00, p = .004), and the corrugator muscle activity to negative social pictures (β = .27, R 2 = .07, t = 1.99, p = .05). The results suggest that the electromyographic activity of the facial muscles is an objective indicator of affective empathy. The increase in the activity of the zygomatic and corrugator muscles in people with high affective empathy, when they observe stimuli with different social content, can be supported by the mirror neuron system and the theory of simulation as an explanatory mechanism of empathy. The mirror neuron system is composed of a complex network of visual areas in the occipital, parietal and temporal regions and two predominantly motor regions, which interact to generate movements similar to those observed, in this case the facial expressions of the stimuli. This response in facial mimicry induces affective states similar to those observed, which leads to a response of affective empathy. Finally, the results of the present study do not support the hypothesis of a desensitization in the participants to negative social stimuli due to the fact of being Colombian, because independently of the level of affective empathy, all of them responded with greater activity of the corrugator muscle to negative social pictures in comparison with neutral and positive pictures. However, as shown in the results, this response was significantly higher in participants with high affective empathy. This result cannot be generalized to the entire Colombian population, given the small size of the sample and its origin. Overall, the results suggest that responses of the zygomatic and corrugator muscles to stimuli with different social content are reliable indicators of affective empathy, and can be used as physiological markers of this kind of empathy in neuroscience and psychophysiology research. No evidence of desensitization was found toward aversive social stimuli in this sample.

Low force exercise training using muscle stimulation adapts physiologic phenotype in people with Spinal Cord Injury

Physical activity, even in short bursts, is critical to maintain human skeletal muscle. Low physical activity levels are associated with poor health, chronic non‐communicable diseases (NCDs), and impaired cognition in people with intact nervous systems as they age. Exercise as a form of medicine increases physical activity levels, attenuates the development of NCDs, and improves cognitive capacity. Because people with spinal cord injury (SCI) cannot volitionally activate their paralyzed muscles, the musculoskeletal system deteriorates with an increased risk for NCDs and cognitive decline as they age. High force electrically induced exercise is risky; therefore, a safe low‐force alternative is needed. Whether training using a low‐force electrically induced exercise can influence muscle and systemic health markers in people with SCI is unknown.PurposeTo determine if low‐force electrically induced exercise changes the phenotype and metabolic health of paralyzed skeletal muscle in people with SCI.Methods10 people with complete SCI completed electrically induced exercise training using low‐force (3Hz) stimulation of the quadriceps. Participants targeted at least 5 exercise training sessions per week. A muscle fatigue test and fasting venous blood draw, measuring CRP, insulin, leptin, BDNF, myostatin, and PTH, were performed before and after training. Muscle biopsies were obtained from a trained and untrained vastus lateralis. Gene expression was measured using the Affymetrix HTA 2.0 array from the trained and untrained muscle samples. All participants provided written consent approved by the University of Iowa Institutional Review Board in compliance with the Declaration of Helsinki.ResultsParticipants were compliant completing ~119±19% of the training sessions for ~7.2±1.2 months. There was a ~68% improvement in fatigue after of exercise training compared to baseline (p=0.002). There was a significant increase in the resting gene expression of slow‐twitch proteins MYH6(p=0.023), MYH7(p=0.034), and MYL3(p=0.022) compared to the untrained limb. Serum concentration of CRP, insulin, myostatin, and leptin were decreased by ~74% (p=0.089), ~179%(0.057), ~64%(p=0.096), and ~79%(p=0.021) after exercise training compared to baseline, respectively. Serum BDNF and PTH concentration were increased by ~70%(p=0.093) and ~78%(p=0.048) after exercise training, respectively.ConclusionsLow‐force electrically induced exercise training improved fatigability and phenotype of paralyzed muscle. Consistent with this change, the homeostatic gene expression of slow‐twitch proteins (MYH6, MYH7, and MYL3) were increased, but the transcription factors (PGC1a and MSTN) remained unchanged. Serum biomarkers (CRP, insulin, leptin, BDNF, myostatin and PTH) showed a consistent trend systemic metabolic health after training. Together, this study highlights the potential of low‐force electrically induced exercise to improve the health in people with chronic SCI, though the minimum duration of training required may be delayed compared to other exercises modalities.Support or Funding InformationResearch SupportThis study was funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development: R01HD084645, R01HD082109

The effects of 10,000 voluntary contractions over 8 weeks on the strength of very weak muscles in people with spinal cord injury: a randomised controlled trial

Study designA multi-centred, single-blinded randomised controlled trial.ObjectivesTo determine the effect of 10,000 voluntary contractions over 8 weeks on the strength of very weak muscles in people with spinal cord injury (SCI).SettingsSeven hospitals in Australia and Asia.MethodsOne hundred and twenty people with recent SCI undergoing inpatient rehabilitation were randomised to either a Treatment or Control Group. One major muscle group from an upper or lower limb was selected if the muscle had grade 1 or grade 2 strength on a standard six-point manual muscle test. Participants allocated to the Treatment Group performed 10,000 isolated contractions of the selected muscle group, as well as usual care in 48 sessions over 8 weeks. Participants allocated to the Control Group received usual care alone. Participants were assessed at baseline and 8 weeks by a blinded assessor. The primary outcome was voluntary muscle strength on a 13-point manual muscle test. There were three secondary outcomes capturing therapists’ and participants’ perceptions of strength and function.ResultsThe mean between-group difference of voluntary strength at 8 weeks was 0.4/13 points (95% confidence interval −0.5 to 1.4) in favour of the Treatment Group. There were no notable between-group differences on any secondary outcome.ConclusionTen thousand isolated contractions of very weak muscles in people with SCI over 8 weeks has either no or a very small effect on voluntary strength.

Architecture of the medial gastrocnemius muscle in people who have had a stroke: A diffusion tensor imaging investigation

MRI techniques (diffusion tensor imaging and mDixon imaging) were used to obtain muscle volume, fascicle length, pennation angle, physiological cross-sectional area and curvature in 14 stroke patients (mean age 60 SD 13years) and 18 control participants (mean age 66 SD 12years). On average, the ankle on the paretic side had 11° (95% confidence interval 8 to 13°) less dorsiflexion range than on the non-paretic side, and 6° (1 to 13°) less dorsiflexion range than ankles of control participants. The medial gastrocnemius muscles on the paretic side were, on average, 15% (35.2cm3, 95% confidence interval 5.2 to 65.2cm3) smaller in volume than the muscles on the non-paretic side, and 16% (36.9cm3, 95% confidence interval 3.1 to 70.6cm3) smaller than in control participants. No statistically significant differences between paretic, non-paretic and control muscles were detected for fascicle length, pennation angle, physiological cross-sectional area or curvature. People with hemiparetic stroke and reduced range of motion have, on average, a smaller medial gastrocnemius muscle on the paretic side than on the non-paretic side. Other muscle architectural parameters appear unchanged.

Alterations in mitochondrial functions and morphology in muscle and non-muscle tissues in type 1 diabetes: implications for metabolic health.

What is the topic of this review? Evidence of impaired mitochondrial functions and/or morphology in people with type 1 diabetes across various organ systems. What advances does it highlight? Impairments to mitochondrial functions and morphology may be a primary mechanism underlying the pathophysiology of various complications in people with type 1 diabetes. We recently made the observation that there are significant alterations to the ultrastructure and functions of mitochondria in skeletal muscle of people with type 1 diabetes (T1D). These alterations are proposed to lead to decreased energy production in skeletal muscle during exercise and thus may contribute to the impaired aerobic exercise capacity reported in some people with T1D. This Symposium Review summarizes the evidence that similar alterations also occur in the mitochondria present in organ systems outside skeletal muscle in people with T1D, and that this may contribute to the development and progression of the known complications of T1D, which eventually lead to the reported premature mortality.

Effect of walking with a modified gait on activation patterns of the knee spanning muscles in people with medial knee osteoarthritis

ObjectiveTo evaluate muscle activation patterns and co-contraction around the knee in response to walking with modified gait patterns in patients with medial compartment knee-osteoarthritis (KOA). Design40 medial KOA patients walked on an instrumented treadmill. Surface EMG activity from seven knee-spanning muscles (gastrocnemius, hamstrings, quadriceps), kinematics, and ground reaction forces were recorded. Patients received real-time visual feedback on target kinematics to modify their gait pattern towards three different gait modifications: Toe-in, Wider steps, Medial Thrust. The individualized feedback aimed to reduce their first peak knee adduction moment (KAM) by ≥10%. Changes in muscle activations and medial/lateral co-contraction index during the loading response phase (10–35% of the gait cycle) were evaluated, for the steps in which ≥10% KAM reduction was achieved. ResultsData from 30 patients were included in the analyses; i.e. all who could successfully reduce their KAM in a sufficient number of steps by ≥10%. When walking with ≥10% KAM reduction, Medial Thrust gait (KAM −31%) showed increased flexor activation (24%), co-contraction (17%) and knee flexion moment (35%). Isolated wider-step gait also reduced the KAM (−26%), but to a smaller extent, but without increasing muscle activation amplitudes and co-contraction. Toe-in gait showed the greatest reduction in the KAM (−35%), but was accompanied by an increased flexor activation of 42% and hence an increased co-contraction index. ConclusionGait modifications that are most effective in reducing the KAM also yield an increase in co-contraction, thereby compromising at least part of the effects on net knee load.

Strengthening Program for Foot-ankle Muscles in People With Knee Osteoarthritis

Strengthening Program for Foot-ankle Muscles in People With Knee Osteoarthritis

High-Density Electromyography Provides New Insights into the Flexion Relaxation Phenomenon in Individuals with Low Back Pain

Recent research using high-density electromyography (HDEMG) has provided a more precise understanding of the behaviour of the paraspinal muscles in people with low back pain (LBP); but so far, HDEMG has not been used to investigate the flexion relaxation phenomenon (FRP). To evaluate this, HDEMG signals were detected with grids of electrodes (13 × 5) placed bilaterally over the lumbar paraspinal muscles in individuals with and without LBP as they performed repetitions of full trunk flexion. The root mean square of the HDEMG signals was computed to generate the average normalized amplitude; and the spatial FRP onset was determined and expressed as percentage of trunk flexion. Smoothing spline analysis of variance models and the contrast cycle difference approach using the Bayesian interpretation were used to determine statistical inference. All pain-free controls and 64.3% of the individuals with LBP exhibited the FRP. Individuals with LBP and the FRP exhibited a delay of its onset compared to pain-free controls (significant mean difference of 13.3% of trunk flexion). They also showed reduced normalized amplitude compared to those without the FRP, but still greater than pain-free controls (significant mean difference of 27.4% and 11.6% respectively). This study provides novel insights into changes in lumbar muscle behavior in individuals with LBP.

Association of electromyographic activation patterns with pain and functional disability in people with chronic neck pain

This study examined the activation patterns of the cervical and thoracic muscles in people with and without chronic neck pain during functional activities and their associations with pain intensity and functional disability. Thirty-four adults with chronic neck pain and 34 asymptomatic adults were recruited. They were requested to perform active cervical movements and an upper limb lifting task. Electromyographic activation patterns (EMG) of bilateral upper trapezius, cervical erector spinae, sternocleidomastoid, and thoracic erector spinae were recorded during these tasks. Correlation and multiple regression analysis were used to examine the associations between EMG variables and severity of pain and functional disability. When performing the cervical movements, the neck pain group displayed lower EMG activity levels, especially in the cervical and thoracic extensors. In addition, significantly prolonged activation was observed in seven of the ten muscles during the upper limb lifting task. The changes in EMG amplitude and activation duration were found to be significantly correlated with severity of pain (R2 = 0.716) and functional disability (R2 = 0.623). Significant differences in the activation patterns of multiple cervical and thoracic muscles were found in individuals with neck pain compared with those without neck pain. These were significantly associated with their degree of pain and functional limitation. The findings of this study highlight the importance of assessing and optimising the neuromuscular activation of these muscles in the rehabilitation of those suffering from chronic neck pain.

Fatigability of the Dorsiflexor Muscles in People with Type 2 Diabetes and Controls

Fatigability of the Dorsiflexor Muscles in People with Type 2 Diabetes and Controls

S99. Reliability of surface electromiography measures for latissimus dorsi, femoral biceps and paraspinal muscles in persons with low back pain

Eighty percent of the population have experienced at least one episode of low back pain (LBP) in their lifetime and approximately 13–19% of adults complain of suffering LBP associated to lifting loads. Latissimus dorsi (LD), femoral biceps (FB) and the paraspinal muscles (PS), have an important role in the stability of the lumbosacral spine. It has been observed that during daily life activities the muscles show different electromyographic responses, depending on factors such as the health condition in which they are studied and the posture in which the measurement is made, among others.The surface electromyography (sEMG) is a non-invasive method that assesses muscle activation and provides relevant information that helps to understand the motor control in people with idiopathic chronic LBP; however, there are no reports in literature about the sEMG reliability during lifting a load for the above-mentioned muscles in people with chronic LBP. Objective: to determine the inter-session reliability of the sEMG for LD, FB and PS muscles, during lifting a load in people with chronic LBP. There were included 10 people (7 women and 3 men) with chronic LBP, between 18 and 40 years (32 ± 4.1) and body mass index 27.4 ± 6.04. The sEMG activity of the LD, FB and PS muscles was assessed while lifting a load in a symmetrical bipedal position in two sessions, with five days between each assessment. The Root mean square (RMS) amplitude and the latency were calculated. The inter-session reliability was assessed through Intraclass Correlation Coefficient (ICC) 2,1 and Bland–Altman analysis. Surface EMG measurements presented moderate to good reliability in latency measures for all assessed muscles (ICC 0.49–0.77 for LD, 0.46–0.56 for FB and 0.59–074 for PS muscles) and displayed moderate to excellent reliability for the RMS amplitude (ICC values 0.46–0.8 for LD; 0.42–0.55 for FB and 0.43–0.68 for PS muscles). Bland–Altman analysis showed a mean value of the difference close to zero and limits of agreement between 2 and 4 ms. The sEMG is a reliable tool that can be useful to evaluate muscle activation during a functional activity, in order to help to understand the muscle activation patterns in people with idiopathic chronic LBP.

Effect of tendon vibration during wide-pulse neuromuscular electrical stimulation (NMES) on muscle force production in people with spinal cord injury (SCI)

BackgroundNeuromuscular electrical stimulation (NMES) is commonly used in skeletal muscles in people with spinal cord injury (SCI) with the aim of increasing muscle recruitment and thus muscle force production. NMES has been conventionally used in clinical practice as functional electrical stimulation (FES), using low levels of evoked force that cannot optimally stimulate muscular strength and mass improvements, and thus trigger musculoskeletal changes in paralysed muscles. The use of high intensity intermittent NMES training using wide-pulse width and moderate-intensity as a strength training tool could be a promising method to increase muscle force production in people with SCI. However, this type of protocol has not been clinically adopted because it may generate rapid muscle fatigue and thus prevent the performance of repeated high-intensity muscular contractions in paralysed muscles. Moreover, superimposing patellar tendon vibration onto the wide-pulse width NMES has been shown to elicit further increases in impulse or, at least, reduce the rate of fatigue in repeated contractions in able-bodied populations, but there is a lack of evidence to support this argument in people with SCI.MethodsNine people with SCI received two NMES protocols with and without superimposing patellar tendon vibration on different days (i.e. STIM and STIM+vib), which consisted of repeated 30 Hz trains of 58 wide-pulse width (1000 μs) symmetric biphasic pulses (0.033-s inter-pulse interval; 2 s stimulation train; 2-s inter-train interval) being delivered to the dominant quadriceps femoris. Starting torque was 20% of maximal doublet-twitch torque and stimulations continued until torque declined to 50% of the starting torque. Total knee extensor impulse was calculated as the primary outcome variable.ResultsTotal knee extensor impulse increased in four subjects when patellar tendon vibration was imposed (59.2 ± 15.8%) but decreased in five subjects (− 31.3 ± 25.7%). However, there were no statistically significant differences between these sub-groups or between conditions when the data were pooled.ConclusionsBased on the present results there is insufficient evidence to conclude that patellar tendon vibration provides a clear benefit to muscle force production or delays muscle fatigue during wide-pulse width, moderate-intensity NMES in people with SCI.Trial registrationACTRN12618000022268. Date: 11/01/2018. Retrospectively registered.

Immediate Effect of Lumbar Mobilization on Activity of Erector Spinae and Lumbar Multifidus Muscles

ObjectiveThe purpose of this study was to investigate the effect of grade IV lumbar mobilization on the activity/contraction of erector spinae (ES) and lumbar multifidus (LM) muscles in healthy people. MethodsA randomized, repeated-measures design was used. Sixteen healthy subjects attended 3 testing sessions with a different intervention in each session (no intervention, grade IV central lumbar mobilization at L4, and placebo/light touch). Lying in a prone position, subjects lifted a light weight with their right arm while ultrasound images of LM and surface electromyography signals of ES were captured before and immediately after application of the intervention in the session. The contraction of LM was calculated from US images, and the root mean square was calculated from the electromyography signals of ES and used as outcome measures. ResultsA significant difference was found in LM contraction between the placebo and mobilization intervention (difference = 0.04, P = .02). There was no difference for the root mean square of electromyography signals between the interventions. ConclusionThe significant difference in LM contraction was small and may not have clinical significance. Lumbar mobilization did not change the activity of ES in healthy people. Future studies with larger samples are needed to confirm our findings and to investigate the effect of mobilization on back muscles in people with low back pain.

Does Neuromuscular Electrical Stimulation Therapy Increase Voluntary Muscle Strength After Spinal Cord Injury? A Systematic Review.

Background: Physical therapists frequently use neuromuscular electrical stimulation (NMES) therapy in an effort to increase the voluntary strength of partially paralyzed muscles in people with spinal cord injury (SCI), but it is not clear whether this treatment is effective. Objective: To determine the effectiveness of NMES for increasing voluntary strength in the partially paralyzed muscles of people with SCI. Methods: A systematic review of scientific literature was conducted in MEDLINE, CINAHL, PEDro, ScienceDirect, and Embase. Inclusion criteria were randomized controlled trials and controlled trials that compared NMES aimed at increasing strength in partially paralyzed muscles versus placebo/nothing or versus a nonstrengthening intervention or versus any other type of strengthening intervention in adults with SCI. Results: Five studies were included. Two studies found an increase in strength measured by peak force and manual muscle force test after an NMES protocol. One study found a between-group difference in favor of the NMES associated with progressive resistance training, and the other study showed an increase in the number of muscles improved by at least 1 degree of strength after NMES in combination with a cycle ergometer. The other 3 studies made several comparisons and found no differences between groups that received NMES and the controls. Conclusions: There is some suggestion that NMES increases voluntary strength in partially paralyzed muscle following SCI. However, there is no strong evidence to affirm the superiority of NMES over other treatment strategies used to gain strength in partially paralyzed muscles after SCI. These findings need replicating in large high-quality randomized controlled trials.

Topographical Pressure Pain Sensitivity Maps of the Temporalis Muscle in People with Frequent Episodic and Chronic Tension‐Type Headache

Previous pilot studies suggest the presence of heterogeneous sensitivity to pressure in primary headaches without considering the frequency of headache episodes. To investigate the differences in topographical pressure pain sensitivity maps in the temporalis muscle between individuals with frequent episodic (FETTH) and chronic (CTTH) tension-type headache by controlling the presence of anxiety and depression. oPressure pain thresholds (PPTs) were assessed bilaterally from 9 points distributed over the temporalis muscle (3 points in the anterior portion, 3 in the middle portion, and the remaining 3 in the posterior portion of the muscle belly) in 113 patients with FETTH and 91 with CTTH in a blinded design. Topographical pressure pain sensitivity maps based on interpolation of the PPTs were constructed. Clinical features of headache were collected in a 4-week headache diary. Anxiety and depression (Hospital Anxiety and Depression Scale) were also assessed. The multilevel analysis of covariance found significant difference in PPT levels between points (F = 47.649; P < 0.001), but not between groups (F = 0.801; P = 0.602) or sides (F = 0.331; P = 0.565). No significant effect of gender (F = 0.785; P = 0.667), depression (F = 0.515; P = 0.846), or anxiety (F = 0.639; P = 0.745) was observed. Post hoc comparisons revealed: (1) no differences between FETTH and CTTH; (2) no side-to-side differences; and (3) anterior-to-posterior gradient with the most sensitive points located in the anterior column, followed by those located in the central column and the posterior column of the muscle (all, P < 0.001). This study confirmed an anterior-to-posterior gradient of sensitivity to pressure in both groups, with the highest sensitivity at the anterior part of the muscle. Further, we found similar pressure pain sensitivity in the trigeminal area in people with FETTH or CTTH with no association with depressive or anxiety levels.

Primary Motor Cortex Organization Is Altered in Persistent Patellofemoral Pain.

Reorganization of the primary motor cortex (M1) may be a feature of persistent patellofemoral pain (PFP), but no studies have investigated M1 organization in this condition. Here we aimed to examine the organization of the M1 representation of the quadriceps muscles in people with PFP and healthy controls. Using a cross-sectional design, the M1 representation of the rectus femoris, vastus lateralis, and vastus medialis was mapped using transcranial magnetic stimulation in 11 individuals with PFP and 11 controls. Measures of pain severity were also made. Individuals with PFP had reduced map volumes (P < 0.001) and an anterior shift in the M1 representation (P = 0.03) across all three quadriceps muscles compared with controls. Greater overlap of the M1 representation (P = 0.02) and a reduction in the number of discrete cortical peaks (P = 0.009) across all three quadriceps muscles were also observed in individuals with PFP compared with controls. There was no relationship between altered M1 organization and pain in PFP. These findings provide evidence of altered M1 organization in individuals with PFP compared with healthy controls. Notably, no difference in M1 organization was observed for the medial and lateral heads of the quadriceps in PFP. These data have relevance for our understanding of the pathophysiology of PFP and for the design of future treatments that aim to target M1 in this condition.

Strength training for partially paralysed muscles in people with recent spinal cord injury: a within-participant randomised controlled trial.

Within-participant randomised controlled trial. To determine whether strength training combined with usual care increases strength in partially paralysed muscles of people with recent spinal cord injury (SCI) more than usual care alone. SCI units in Australia and India. Thirty people with recent SCI undergoing inpatient rehabilitation participated in this 12-week trial. One of the following muscle groups was selected as the target muscle group for each participant: the elbow flexors, elbow extensors, knee flexors or knee extensors. The target muscle on one side of the body was randomly allocated to the experimental group and the same muscle on the other side of the body was allocated to the control group. Strength training was administered to the experimental muscle but not to the control muscle. Participants were assessed at baseline and 12 weeks later. The primary outcome was maximal isometric muscle strength, and the secondary outcomes were spasticity, fatigue and participants' perception of function and strength. There were no dropouts, and participants received 98% of the training sessions. The mean (95% confidence interval (CI)) between-group difference for isometric strength was 4.3 Nm (1.9-6.8) with a clinically meaningful treatment effect of 2.7 Nm. The mean (95% CI) between-group difference for spasticity was 0.03/5 points (-0.25 to 0.32). Strength training increases strength in partially paralysed muscles of people with recent SCI, although it is not clear whether the size of the treatment effect is clinically meaningful. Strength training has no deleterious effects on spasticity.