The effect of elbow flexion speed and partial limb occlusion on EMG activity

This investigation aimed to determine the neuromuscular response of the bicep brachii during heavy (6RM) dynamic resistance exercise performed to volitional exhaustion. Electromyographic (EMG) activity was compared in twelve male subjects performing dominant-limb elbow flexion exercise during four conditions: i) Explosive concentric and eccentric (SSC); ii) Explosive concentric, control eccentric (EC); iii) control (C); and iv) control with limb occlusion (CO) (110mmHg). CO and SSC are reported to increase motor unit activity when compared to control exercise (2 second flexion, 2 second extension). It was hypothesised that EMG activity will be higher in conditions of explosive exercise. Surface EMG activity was collected (Digitmer, Neurolog NL844, NL820) at 2 kHz and filtered using 500Hz (low-pass) and 10Hz (high-pass) filters (Digitimer, Neurolog NL44, NL135). Root mean square (RMS) significantly increased; SSC=71.0 ±14.9% (P=0.004), EC=52.8 ±10.0% (P=0.001), C=44.4 ±11.1% (P=0.007), CO=33.9 ±11.1% (P=0.025) and mean power frequency (MPF) significantly decreased; SSC=36.0 ± 4.2Hz (P=0.001), EC=18.0 ± 3.8Hz (P=0.002) C=17.9 ± 3.4Hz (P=0.001), CO=20.3 ± 3.2Hz (P=0.001) from the first to last repetition. The first repetition of SSC exercise displayed significantly higher MPF (17.4 ± 4.0Hz, P= 0.009) compared to C. RMS was significantly different in CO to SSC exercise (34.9 ± 10.5%, P=0.048) at the final repetition. SSC exercise demonstrated the greatest EMG response to exhaustive heavy resistance exercise and is attributed to an increase in motor unit recruitment and discharge rate. The lack of an observed difference between the EC and C exercise suggests eccentric limb speed is important for concentric muscle activation

Feasibility of Virtual Reality Exercises at Home for Post-COVID-19 Condition: Cohort Study

BACKGROUND: Between 30% to 76% of COVID-19 patients have persistent physical and mental symptoms, sometimes up to 9 months after acute COVID-19. Current rehabilitation is mostly focused on the physical symptoms, whereas experts have agreed on the need for a biopsychosocial approach. A novel approach such as virtual reality (VR) rehabilitation at home might benefit patients and therapists, especially considering the expected rush of patients with post-COVID-19 condition needing rehabilitation. OBJECTIVE: The aim of this study was to investigate the feasibility of self-administered VR exercises at home for post-COVID-19 condition. METHODS: This was a single-arm feasibility study in an outpatient care setting. Patients who needed physiotherapy because of post-COVID-19 condition were included as determined by the treating physiotherapist. Participants performed VR physical exercises at home for a period of 6 weeks and were allowed to perform VR mental exercise through applications available on the VR platform to reduce stress and anxiety and promote cognitive functioning. The main outcomes were related to feasibility (ie, duration and frequency of VR use), safety (ie, adverse events), patient satisfaction, and reasons to withdraw. Physical performance, daily activities, cognitive functioning, anxiety and depression, and the quality of life were measured before and after. RESULTS: In total, 48 patients were included; 1 (2%) patient did not start VR, and 7 (15%) patients withdrew, mostly due to dizziness. Almost 70% (33/47) of participants reported experiencing any adverse event during VR exercising. However, only 25% (9/36) recalled these events at the end of the intervention period. The majority (27/36, 75%) of the patients described VR as having a positive influence on their recovery, and the global satisfaction score was 67%. The average VR use was 30 minutes per session, 3-4 times a week for 3-6 weeks. The overall use of VR applications was almost equally distributed over the 3 sets of VR exercises (physical, relaxing, and cognitive). However, the use frequency of physical exercises seemed to decrease over time, whereas the use of cognitive and relaxation exercises remained stable. Physical performance and quality of life outcomes were significantly improved after 6 weeks. CONCLUSIONS: VR physical exercises at home is feasible and safe with good acceptance in a significant percentage of patient with post-COVID-19 condition. TRIAL REGISTRATION: ClinicalTrials.gov NCT04505761; https://clinicaltrials.gov/ct2/show/NCT04505761

Exercise-based cardiac rehabilitation in patients with coronary heart disease: a practice guideline

To improve the quality of exercise-based cardiac rehabilitation (CR) in patients with coronary heart disease (CHD) the CR guideline from the Dutch Royal Society for Physiotherapists (KNGF) has been updated. This guideline can be considered an addition to the 2011 Dutch Multidisciplinary CR guideline, as it includes several novel topics. A systematic literature search was performed to formulate conclusions on the efficacy of exercise-based interventions during all CR phases in patients with CHD. Evidence was graded (1-4) according the Dutch evidence-based guideline development (EBRO) criteria. In case of insufficient scientific evidence, recommendations were based on expert opinion. This guideline comprised a structured approach including assessment, treatment and evaluation. Recommendations for exercise-based CR were formulated covering the following topics: preoperative physiotherapy, mobilisation during the clinical phase, aerobic exercise, strength training, and relaxation therapy during the outpatient rehabilitation phase, and adoption and monitoring of a physically active lifestyle after outpatient rehabilitation. There is strong evidence for the effectiveness of exercise-based CR during all phases of CR. The implementation of this guideline in clinical practice needs further evaluation as well as the maintenance of an active lifestyle after supervised rehabilitatio