WHO working group defines Long COVID (LC) as symptoms experienced for more than 12 weeks after the provable or confirmed diagnosis of COVID-19 that can’t be explained with any other diagnosis. With the progression of time, the global prevalence of long COVID symptoms (LCS) is increasing from 10 to 36 percent. ¹ Between 16.2% and 25.2% of Bangladeshi people are experiencing LCS. ^{2 , 3} The respondents reported a broad spectrum of LCS, those were reported as fatigue, musculoskeletal pain, headache, loss of concentration, anxiety, depression, and post-exertion dyspnea. The presentation of LCS was noted as a relapsing remittent nature, which might not be described as related to a single biological system or organ involvement in the human body. With each relapsing episode, LCS had new symptoms, and symptoms were reported to be lasting more than a year. ⁴ The management of LCS is multidisciplinary, as it has impacts on multiple organs in humans. ⁵ WHO living guideline reports, rehabilitation is the key to managing the persistent illness that interferes with body function, daily activities, and overall quality of life. This guideline also states rehabilitation is an integral part of universal health and well-being and the global scope of rehabilitation stands for 2.4 billion people; 50% of the people living in lower-middle-income countries are out of reach of the scope. In the household LCS survey, Bangladeshi people had significant impairments in the musculoskeletal, neurological, and cognitive domains, ⁴ and there is an emerging scope of physiotherapy and rehabilitation. Moreover, managing this significant scope will be another challenge because the COVID-19 pandemic changed the paradigm of rehabilitation service by adding a set of new impairments within the spectrum of rehabilitation. ⁶

In a lower middle-income country like Bangladesh, it is important to study symptom responses and impairments to determine the scope of rehabilitation and generate clinical trials and shreds of evidence. From recent studies in Bangladesh, ^{2 , 3} we understand the symptom responses, disease spectrum, and scope of rehabilitation but there are inconclusive answers on the rehabilitation interventions for LCS. From the fact sheets of WHO, we know rehabilitation interventions play an important for the clinical management of LCS. To elicit the outcome of rehabilitation, clinical trials are necessary. And to design the trial interventions and achieve the greater clinical benefit, a review of the literature and consensus is important. There is a research gap in studies focusing on physiotherapy and rehabilitation interventions for LCS, and this comprehensive systematic scoping can address the research gap.

This study aims to determine the physiotherapy and rehabilitation interventions in the management of (1) musculoskeletal symptoms, (2) neurological and cognitive symptoms, (3) cardiorespiratory symptoms, (4) mental health issues, and (5) Functional limitations for Long COVID.

We conducted a systematic scoping review of the literature published between April 2020 and July 2022. To maintain the rigor of the paper we followed Preferred Reporting Items for Systematic reviews and meta-analysis (PRISMA) extension for Scoping reviews (PRISMA-ScR) (Extended data 1 ¹⁰⁰ ).

The discussion section is narrated into 5 categories where we present perspectives around (1) the management of musculoskeletal symptoms, (2) the management of neurological and cognitive symptoms, (3) the management of cardiorespiratory symptoms, (4) the management of mental health issues, and (5) Functional rehabilitation. Detailed interventions are provided in the extended data 8.

Management of Musculoskeletal impairments is focused on pain, fatigue, muscle loss, muscle weakness, and fatigue. Self-directed exercise and lifestyle advice prescribed through telemedicine or in-person consultation was recommended for managing chronic pain in LCS. ²² To battle chronic pain along with physical limitations and low exercise tolerance, strengthening exercises, multi-component training, and guided walking practice were recommended. ^{28 , 50} Pain associated with myalgia and arthralgia was advised to be treated by neuromuscular exercises, however, functional electrical stimulation (FES) can be promising to restore function and muscle performance. ³⁶ For musculoskeletal pain, studies suggest ^{42 , 46} aerobic exercise and respiratory re-education, and pacing exercises as an initial bout, progressing to strengthening, pelvic bridging, and core stability exercises. These interventions are also effective in managing generalized pain associated with lower back pain and sudden weight gain. ^{42 , 46} Fatigue, muscle pain, and muscle weakness were the commonly reported symptoms, and a wide range of manual therapy, manipulative therapy, exercise therapy, and electrotherapy was suggested. ^{24 , 25 , 41 , 50 , 58 , 62} Manual and manipulative therapy approaches included soft tissue techniques, relaxation techniques, release techniques, and trigger point therapy. Exercise therapy included aerobic training, range of motion exercise, and dynamic muscle training. Respiratory exercises were suggested as pacing, deep breathing exercise, thoracic expansion exercise, and aerobic exercise. Swimming and hydrotherapy were also suggested for LCS cases with myalgia and fatigue. Neuromuscular electrical stimulation (NEMS) was found to be effective in managing fatigue-related weakness, fatigue associated with neuromuscular weakness. Fall is a consequence of neuromuscular weakness and fall prevention strategies included passive range of motion exercises progressing to active range of motion exercises and strengthening exercises. ³⁶ To prevent muscle loss rated to long-term physical inactivity and frailty ²⁷ early mobilization and positioning in ICU were found to be effective. To manage sarcopenia, ⁴⁸ aerobic exercise, resistance training, a multidisciplinary approach of physiotherapy, nutrition, and cognitive behavioral therapy were recommended.

Major neurological symptoms and consequences were anosmia, ageusia, headache, cerebrovascular accidents, Guillain-Barré syndrome, seizures, and encephalopathy, ^{14 , 15 , 21 , 23} and recommended exercises were neuro-physiotherapy interventions, motor training exercises, balance, and coordination practice, walking training, music therapy and robotic rehabilitation through the in-person or telerehabilitation approach. For these conditions, cognitive behavioral therapy was also recommended. Headache was another prominent symptom, ^{28 , 35} the study recommended relaxation through breathing exercises, diaphragmatic breathing, and exercise therapy as aerobic exercise, and strengthening or vigorous physical exercise was effective. However, mindfulness training and resistance training improves memory loss. ^{35 , 64}

A variety of interventions were recommended for cardio-respiratory impairments. To manage primary dyspnea ^{16 , 18 , 20 , 24 , 29 , 30 , 63} breathing exercises such as pursed lip breathing, yoga, and pranayama (ancient Indian technique), and a low-intensity pulmonary rehabilitation program were recommended. Managing dyspnea as LCS needs to cover a comprehensive approach ^{35 , 39 , 40 , 41 , 42 , 47 , 57 , 60 , 70} on aerobic training, strengthening exercises, diaphragmatic breathing techniques, and mindfulness training. Moreover, stretching exercises, warm-up, breathing exercises, resistance training, respiratory rehabilitation, respiratory muscle training exercises, coughing exercises, slow, deep, and sustained inhalations, patient Education, functional activity training, and behavioral changes were found to be significant. In case of chest pain associated with fatigue or breathlessness ^{23 , 24 , 26 , 31 , 38 , 46} intervention starts with primary healthcare management with medical screening, meditation, and gradual pacing of stretching exercises, strengthening exercises, stretching exercises, resistant training, coping and ADL strategies (including management of energy and drive functions), ES, FES cycling was recommended. If there are productive cough with dyspnea ^{25 , 31 , 38 , 53} recommended treatments were bronchial hygiene techniques such as assisted cough, postural drainage, and percussion, breathing exercises and mobilization, active-assisted or active ROM exercises, achieving mobilization, whole body muscle strengthening exercises, incentive spirometry for patients having sputum and productive cough. The utilization of devices for individual use such as Tri-flow, flutter breathing device, acapella, cornet, positive expiratory pressure (PEP), aerobic exercises, strength exercises, and resistance training were effective. In case of shortness of breath, ^{26 , 62} goal-directed therapy should be applied. Dyspnea associated with fatigue and tachycardia can be managed by oxygen therapy, noninvasive ventilation, spontaneous prone positioning, and early mobilization. Oxygen therapy and pacing are recommended for low saturation levels and hypoxia. ⁵⁶

Anxiety and depression ^{17 , 18 , 26 , 41 , 42 , 54} were the most prominent issues in LCS cases. The issues can be managed by respiratory rehabilitation, aerobic training, hydrotherapy, and thermotherapy coping and ADL strategies (including management of energy and drive functions), strength exercises, resistance training, postural gymnastics, and respiratory re-education. Mood disturbances and sleep disturbances ^{24 , 36 , 41 , 50} can be managed by cycle ergometer exercises and muscular strengthening, aerobic exercises, strength exercises, resistance training, and vibration exercises. Impairments in the functional status due to sleep issues, ²⁴ and functional capacity issues ²⁷ can be managed through proper primary care management, along with aerobic training, hydrotherapy and thermotherapy, coping, and ADL strategies (including management of energy and drive functions).

The review found a multi-directional and multi-professional role in LCS. But we focused on the treatment regimen of physiotherapy, related therapy, and rehabilitation perspectives. Our study met the research gap on the large-scale rehabilitation intervention-focused review that was insufficient and with a small scale in the previous reviews. ^{94 – 96} To our best knowledge, this is the larger scale review of LCS focused on rehabilitation interventions concerning the number of included papers and study population. We did not measure the sources of bias in the included study separately, instead, we evaluated the papers with a comprehensive appraisal by our appraisal tools for each type of included study following EQUATOR guidelines (Extended data 2-7). Scoping reviews do not require a complete appraisal and evaluation of the strength of included articles, ⁹⁷ we have included additional analysis to present the reader with a comprehensive scenario of the intervention recommendations and the strength of information sources. The appraisal tool was an innovative concept. There are a few appraisal tools, mostly for randomized control trials or reviews, ^{98 , 99} our appraisal scoring was for cross-sectional, case-control, cohort, randomized control trials, study protocols, and Delphi-consensus. The scoring tools had no psychometric validation yet, but the system has a significant rigor as they are designed and adhered to the established EQUATOR guideline. A different type of study was evaluated with different scoring parameters, to present a uniform approach, the score was converted between 0 and 1. In that appraisal scoring evaluation, the minimum score of included studies was 0.6 out of 1. That means the lowest quality articles included in this study had 60% adherence to the EQUATOR standard for reporting research. According to the adjusted score, there was not any single specific intervention was recommended for long COVID rehabilitation, management of underlying symptoms especially fatigue through multidisciplinary rehabilitation was the most weighted recommendation. However, aerobic exercise, balance training, and low-resistance exercise were mostly recommended. NICE guidelines strongly recommended not to use resistance exercise or graded exercise for long COVID patients having chronic fatigue syndrome, as it can provoke post-exertion symptom exacerbation.

The primary limitation of the study was the insufficiency of randomized control trials, and level I studies. Long COVID is a relatively new term and clinical evidence is yet to be explored, hence we had a few pieces of evidence due to our focus on physiotherapy and rehabilitation. The future study recommendations will be systematic reviews and meta-analyses on RCTs or cohorts of LCS. Our most weighted recommended interventions do not completely adhere to NICE guidelines in the means of resistance training, but low resistance training can’t be entitled as graded exercise, as it can be prescribed as a part of pacing with careful observation. Moreover, the paradigm of long covid rehabilitation needs more clinic-based and community-based trials.

Long COVID is recommended to be managed by a multidisciplinary approach by treating the individual symptoms, especially fatigue. There is significant scope for physiotherapy in long COVID, as most of the recommended interventions were exercise, electro-physical agents, respiratory physiotherapy and telerehabilitation. Physiotherapy and rehabilitation interventions can be provided at home or in clinical setups such as primary care settings, specialized rehabilitation services, community care, and telerehabilitation by physiotherapists only or as a part of the multidisciplinary team. Current understanding is limited to the appropriate doses of rehabilitation interventions and the long-term outcome of rehabilitation.