Comparative effects of EMG-driven robot-assisted therapy versus task-oriented training on motor and daily function in patients with stroke: a randomized cross-over trial

Background Robot-assisted hand training has shown positive effects on promoting neuromuscular control. Since both robot-assisted therapy and task-oriented training are often used in post-stroke rehabilitation, we raised the question of whether two interventions engender differential effects in different domains. Methods The study was conducted using a randomized, two-period crossover design. Twenty-four chronic stroke survivors received a 12-session robot-assisted intervention followed by a 12-session task-oriented intervention or vice versa. A 1-month washout period between each intervention was implemented. Outcome measures were evaluated before the intervention, after the first 12-session intervention, and after the second 12-session intervention. Clinical assessments included Fugl-Meyer Assessment for Upper Extremity, Wolf Motor Function Test, Action Research Arm Test and Motor Activity Log. Results Our findings suggested that EMG-driven robot-assisted therapy was as effective as task-oriented training in terms of improving upper limbs functional performance in activity domain, and robot-assisted therapy was more effective in improving movement duration during functional tasks. Task-oriented training showed better improvement in body function domain and activity and participation domain, especially in improving spontaneous use of affected arm during daily activities. Conclusions Both intervention protocol had their own advantages in different domains, and robot-assisted therapy may save manpower and be considered as an alternative intervention to task-oriented training. Combining the two approaches could yield results greater than either alone, which awaits further study. Trial registration: ClinicalTrials.gov Identifier: NCT03624153. Registered on 9th August 2018, https://clinicaltrials.gov/ct2/show/NCT03624153.

Proprioception and neuromuscular control at return to sport after ankle surgery with the modified Broström procedure

The modified Broström procedure (MBP) is an initial treatment for symptomatic chronic ankle instability (CAI) patients. This study aimed to compare the proprioception and neuromuscular control ability of both affected and unaffected ankles at the time of return to sports after MBP for patients with scores of normal controls. 75 individuals (40 who underwent MBP, 35 normal controls) participated. The dynamic balance test scores were significantly higher in the affected ankle of the patients than in the controls (1.5 ± 0.6° vs. 1.1 ± 0.4°, p < 0.003). The time to peak torque for dorsiflexion (60.8 ± 13.9 ms vs. 52.2 ± 17.5 ms, p < 0.022) and eversion (68.9 ± 19.1 ms vs. 59.3 ± 21.1 ms, p < 0.043) was significantly delayed in the affected ankle of the patients than in the controls. The dynamic balance test and time to peak torque in CAI patients remained significantly reduced at the time of return-to-sport after MBP. Clinicians and therapists should be aware of potential deficits in proprioception and neuromuscular control when determining the timing of return to sports after MBP.

Neuromuscular Impairment of Knee Stabilizer Muscles in a COVID-19 Cluster of Female Volleyball Players: Which Role for Rehabilitation in the Post-COVID-19 Return-to-Play?

COVID-19 athletes reported persistent and residual symptoms many weeks after initial infection, including cough, fatigue, and neuromuscular disorders. Poor neuromuscular control may cause inefficient movement strategies increasing anterior cruciate ligament load. This is particularly relevant in female athletes, who show a 3-time higher risk than male counterparts. Aim is to evaluate the impairment in thigh muscles activation, body composition, and physical performance after COVID-19 in volleyball athletes. We recruited a cohort of female professional players from the same team. We assessed the pre-activation time of Rectus Femoris (RF), Vastus Medialis (VM), Medial Hamstring (MH), and Lateral Hamstring (LH) before (T0) and after (T1) COVID-19 infection, bioelectrical impedance analysis (BIA), and jump tests. We included 12 athletes with COVID-19 infection diagnosis in January 2021. At T1 we found a significant (p < 0.05) delay (ms) of the activation time of RF (426 ± 188 vs. 152 ± 106); VM (363 ± 192 vs. 140 ± 96); BF (229 ± 60 vs. 150 ± 63); MH (231 ± 88 vs. 203 ± 89), and a significant reduction of body composition at BIA. The neuromotor imbalance of the knee stabilizer muscle in female athletes after COVID-19 infection determines a deficit of knee stabilization. Physicians should consider neuromuscular and metabolic sequelae to identify athletes at higher risk of injury and set up specific neuromuscular rehabilitation protocols.

The neuromuscular responses in patients with Parkinson’s disease under different conditions during whole-body vibration training

Background Whole-body vibration (WBV) training can provoke reactive muscle response and thus exert beneficial effects in various neurological patients. This study aimed to investigate the muscles activation and acceleration transmissibility of the lower extremity to try to understand the neuromuscular control in the Parkinson’s disease (PD) patients under different conditions of the WBV training, including position and frequency. Methods Sixteen PD patients and sixteen controls were enrolled. Each of them would receive two WBV training sessions with 3 and 20 Hz mechanical vibration in separated days. In each session, they were asked to stand on the WBV machine with straight and then bended knee joint positions, while the vibration stimulation was delivered or not. The electromyographic (EMG) signals and the segmental acceleration from the lower extremity were recorded and processed. The amplitude, co-contraction indexes (CCI), and normalized median frequency slope (NMFS) from the EMG signals, and the acceleration transmissibility were calculated. Results The results showed larger rectus femoris (RF) amplitudes under 3 Hz vibration than those in 20 Hz and no vibration conditions; larger tibialis anterior (TA) in 20 Hz than in no vibration; larger gastrocnemius (GAS) in 20 Hz than in 3 Hz and no vibration. These results indicated that different vibration frequencies mainly induced reactive responses in different muscles, by showing higher activation of the knee extensors in 3 Hz and of the lower leg muscles in 20 Hz condition, respectively. Comparing between groups, the PD patients reacted to the WBV stimulation by showing larger muscle activations in hamstring (HAM), TA and GAS, and smaller CCI in thigh than those in the controls. In bended knee, it demonstrated a higher RF amplitude and a steeper NMFS but smaller HAM activations than in straight knee position. The higher acceleration transmissibility was found in the control group, in the straight knee position and in the 3 Hz vibration conditions. Conclusion The PD patients demonstrated altered neuromuscular control compared with the controls in responding to the WBV stimulations, with generally higher EMG amplitude of lower extremity muscles. For designing WBV strengthening protocol in the PD population, the 3 Hz with straight or flexed knee protocol was recommended to recruit more thigh muscles; the bended knee position with 20 Hz vibration was for the shank muscles.

Examining the Relationship Between a Neuromuscular Control Baseline Battery for Sport-Related Concussion and Anterior Cruciate Ligament Injury Risk

ObjectiveTo examine the relationship between the m-CTSIB and Landing Error Scoring System in a sample of collegiate female athletes.BackgroundRecent literature has linked concussion and neuromuscular deficits in the lower extremity after injury. Neuromuscular control is frequently assessed using balance measures for concussion, but also dynamically to identify anterior cruciate ligament injury (ACL) risk via jump-landing movement screening.Design/MethodsThirty-nine healthy, collegiate female soccer (n = 22) and volleyball (n = 17) athletes completed the modified-Clinical Test of Sensory Interaction of Balance (m-CTSIB) and the Landing Error Scoring System (LESS). Measures consisted of total m-CTSIB sway index scores on individual conditions (firm surface eyes open [condition 1] and eyes closed [2], foam surface eyes open [3] and eyes closed [4]), m-CTSIB overall score, and total LESS errors. LESS scores were also categorized into a low (0–4 errors) and high (5 + errors) risk to determine if athletes with worse neuromuscular control on the LESS has worse balance on the m-CTSIB. A Spearman's rank-order correlation was conducted to determine the strength of the relationship between LESS and m-CTSIB performance. A series of Mann-Whitney U test were performed to determine differences between low and high LESS performance on m-CTSIB performance.ResultsThere was a weak, negative correlation between LESS and m-CTSIB performance (rs(37) = −0.153, p = 0.35). Further, there were no differences between the low and high risk LESS groups on sway index scores on conditions 1 (U = 158.5, p = 0.39), 2 (U = 156.0, p = 0.36), 3 (U = 165.5, p = 0.51), or 4 (U = 128.5, p = 0.08), as well as overall m-CTSIB scores (U = 150.5, p = 0.28).ConclusionsThere appears to be a lack of relationship between the LESS and m-CTSIB tests, revealing the independence of static and dynamic lower extremity neuromuscular function. Athletes who may be more at risk for ACL injury due to abnormal jump-landing biomechanics, do not differ from low-risk athletes on baseline balance assessment.

Acute Whole-Body Vibration Exercise Promotes Favorable Handgrip Neuromuscular Modifications in Rheumatoid Arthritis: A Cross-Over Randomized Clinical

Objective. Rheumatoid arthritis (RA) causes progressive changes in the musculoskeletal system compromising neuromuscular control especially in the hands. Whole-body vibration (WBV) could be an alternative for the rehabilitation in this population. This study investigated the immediate effect of WBV while in the modified push-up position on neural ratio (NR) in a single session during handgrip strength (HS) in women with stable RA. Methods. Twenty-one women with RA (diagnosis of disease: ±8 years, erythrocyte sedimentation rate: ±24.8, age: 54± 11 years, BMI: 28 ± 4 kg ·m-2) received three experimental interventions for five minutes in a randomized and balanced cross-over order: (1) control—seated with hands at rest, (2) sham—push-up position with hands on the vibration platform that remained disconnected, and (3) vibration—push-up position with hands on the vibration platform turned on (45 Hz, 2 mm, 159.73 m·s-2). At the baseline and immediately after the three experimental interventions, the HS, the electromyographic records (EMGrms), and range of motion (ROM) of the dominant hand were measured. The NR, i.e., the ratio between EMGrms of the flexor digitorum superficialis (FDS) muscle and HS, was also determined. The lower NR represented the greater neuromuscular efficiency (NE). Results. The NR was similar at baseline in the three experimental interventions. Despite the nonsignificance of within-interventions ( p = 0.0611 ) and interaction effect ( p = 0.1907 ), WBV exercise reduced the NR compared with the sham and control ( p = 0.0003 , F = 8.86 , η 2 = 0.85 , power = 1.00 ). Conclusion. Acute WBV exercise under the hands promotes neuromuscular modifications during the handgrip of women with stable RA. Thus, acute WBV exercise may be used as a preparatory exercise for the rehabilitation of the hands in this population. This trial is registered with trial registration 2.544.850 (ReBEC-RBR-2n932c).

Quantitative Investigation of Hand Grasp Functionality: Hand Joint Motion Correlation, Independence, and Grasping Behavior

Modeling and understanding human grasp functionality are fundamental in prosthetics, robotics, medicine, and rehabilitation, since they contribute to exploring motor control mechanism, evaluating grasp function, and designing and controlling prosthetic hands or exoskeletons. However, there are still limitations in providing a comprehensive and quantitative understanding of hand grasp functionality. After simultaneously considering three significant and essential influence factors in daily grasping contained relative position, object shape, and size, this paper presents the tolerance grasping to provide a more comprehensive understanding of human grasp functionality. The results of joint angle distribution and variance explained by PCs supported that tolerance grasping can represent hand grasp functionality more comprehensively. Four synergies are found and account for 93 % ± 1.5 % of the overall variance. The ANOVA confirmed that there was no significant individual difference in the first four postural synergies. The common patterns of grasping behavior were found and characterized by the mean value of postural synergy across 10 subjects. The independence analysis demonstrates that the tolerance grasping results highly correlate with unstructured natural grasping and more accurately correspond to cortical representation size of finger movement. The potential for exploring the neuromuscular control mechanism of human grasping is discussed. The analysis of hand grasp characteristics that contained joint angle distribution, correlation, independence, and postural synergies, presented here, should be more representative to provide a more comprehensive understanding of hand grasp functionality.

Muscle Synergies in People With Chronic Ankle Instability During Anticipated and Unanticipated Cutting Tasks

Context: Although neuromuscular deficits in people with chronic ankle instability (CAI) have been identified, previous studies mostly investigated the activation of multiple muscles in isolation. Investigating muscle synergies in people with CAI would provide information about the coordination and control of neuromuscular activation strategies and could hold important information for understanding and rehabilitating neuromuscular deficits in this population. Objective: The purpose of this study was to investigate muscle synergies in people with CAI and healthy controls as they perform different cutting tasks. Design: Cross-sectional study Setting: Laboratory Participants: Eleven people with CAI (22 ± 3 years, 1.68 ± 0.11 m, 69.0 ± 19.1 kg) and 11 healthy controls (CON) (23 ± 4 years, 1.74 ± 0.11 m, 66.8 ± 15.5 kg) participated in the current study. Main Outcome Measures: Muscle synergies were extracted from the EMG of the soleus, medial gastrocnemius, lateral gastrocnemius, tibialis anterior, and fibularis longus muscles during anticipated and unanticipated cutting tasks. The number of synergies, activation coefficients, and muscle-specific weighting coefficients were compared between groups and across tasks. Results: The number of muscle synergies were the same for each group and task. The CAI group exhibited significantly greater (p = 0.023) tibialis anterior weighting coefficients within Synergy 1 compared to the CON group. In addition, both groups exhibited greater fibularis longus (p = 0.029) weighting coefficients within Synergy 2 during unanticipated cutting compared to anticipated cutting. Conclusion: These results suggest that while both groups used a neuromuscular control strategy of similar complexity / dimensionality to perform the cutting tasks, people with CAI exhibited different muscle-specific weightings characterized by greater emphasis on tibialis anterior function within Synergy 1, which may reflect an effort to increase joint stability to compensate for the presence of ankle instability.

Lumbopelvic-Hip Complex Contribution During Lower Extremity Screening Tests in Elite Figure Skaters

ABSTRACT Context: Figure skating requires power and stability for take-off and landing from multi-rotational jumps and various on-ice skills. Repetitive forces may cause overuse injuries distally making lumbopelvic-hip endurance, strength, and neuromuscular control imperative. Objective: The purpose was to compare lumbopelvic-hip endurance and neuromuscular control in elite figure skaters between sex and limbs using common screening tests. Design: Cross-sectional study. Setting: U.S. Olympic and Paralympic Training Center. Participants: Forty elite figure skaters (23.2±4.3 years, 169.1±12.2 cm, 20F, 40R landing limb) performed the Y-balance test, single leg squat (SLS), single leg squat jump (SLSJ), and unilateral hip bridge endurance test. Main Outcome Measures: Normalized reach difference (% of leg length) and composite scores (((Anterior + Posteromedial + Posterolateral)/Limb length x 3) x100) were calculated for Y-balance test. Skaters held the unilateral hip bridge until failure with a maximum allotted time of 120s. Participants performed 5 SLS and SLSJ, barefooted with the contralateral limb held behind them to mimic a landing position. Both tests were scored by the number of times the patella moved medially to the first ray (medial knee displacement (MKD)). MANOVA with post-hoc independent t-tests were performed between groups and sex. Paired t-tests were used to analyze limb differences. Results: Females had a larger composite Y-balance score (R:+10.8, p=.002; L:+10.5, p=.001) and hip bridge hold time (R:+26.4 sec, p=.004; L:+28.2 sec, p=.002) on both limbs compared to males. Males held the hip bridge longer on their landing limb. During the SLS and SLSJ, 6 skaters performed worse on their non-landing limb during the SLS, and 11 skaters had no MKD with either test. Conclusions: Females performed better on the Y-balance and unilateral hip bridge tests. Increased MKD for some skaters in the SLS and SLSJ may indicate hip abductor weaknesses. Understanding proximal lumbopelvic-hip variables during take-off and landing may elucidate contributing factors to distal overuse injuries.