The role of tuning fork in the evaluation of musculoskeletal disorders and pallesthesia: A scoping review.

BACKGROUND: Musculoskeletal and neurological conditions disorders are important conditions that need to be assessed in clinical practice. The tuning fork (TF) has been proposed as a practical tool to investigate suspected fractures and for the evaluation of pallesthesia in subjects with peripheral neuropathy. OBJECTIVE: the aim of this study is to define whether the tuning fork can be useful in the clinical evaluation of patients with musculoskeletal disorders and deep somatosensory dysfunctions. METHODS: This scoping review was performed in accordance with Joanna Briggs Institute. MEDLINE, Cochrane Library, PEDro, CINAHL, Web of Science, UpToDate, Scopus Database were consulted. RESULTS: 14 studies were included in the final analysis. Nine studies regard the use of tuning fork to detect fractures. If the tuning fork was used with a stethoscope, the test reached a high sensitivity ranging between 83% and 94%. Five studies investigated the tool to evaluate pallesthesia dysfunctions among which possible differences between biceps femoris strain and simple clinical rules for detecting peripheral neuropathy. CONCLUSION: The 128 Hz tuning fork could be potentially useful to detect some type of traumatic fractures. The Rydel-Seiffer tuning fork appears to be a useful tool for assessing potential nerve conduction deficits in the evaluation of pallesthesia.

Biomechanical and ergonomic risks associated with cervical musculoskeletal dysfunction amongst surgeons: A systematic review.

INTRODUCTION: Surgeons are at high risk of developing musculoskeletal symptoms due to a range of factors including, maladaptive positioning and surgical ergonomics. Cervical muscle strain and biomechanical load is most prevalent due to repetitive motions and prolonged static neck positioning. This issue is apparent through reports of prevalence between 10 and 74.4% among surgeons. The aim of this systematic review is to provide an objective assessment of the clinical evidence available and a descriptive analysis of the effects of kinematics and surgical ergonomics on the prevalence of surgeons' cervical musculoskeletal pain. METHODS: This is PRISMA-compliant systematic review of clinical studies assessing the prevalence of cervical musculoskeletal dysfunction in surgeons by searching PUBMED and Ovid EMBASE databases from inception to 19th October 2023. Study quality was graded according to the National Institutes of Health study quality assessment tools. RESULTS: A total of 9 studies were included in the final qualitative analysis. The use of loupes, open surgery and excessive neck flexion (>30°) were associated with cervical dysfunction. Comparison of study outcomes was challenging due to heterogeneity within study methods and the paucity of methodological quality. CONCLUSION: The current literature assessing ergonomic and biomechanical factors predisposing surgeons to cervical musculoskeletal dysfunction is insufficient to provide reliable guidance for clinicians. Although the literature identifies factors contributing to work-related cervical dysfunction, few attempt to evaluate interventions for improved surgical ergonomics. An objective assessment of interventions that prompt postural correction with the aim to improve neck pain in surgeon cohorts is warranted.

Safety and feasibility of in-hospital autonomous transportation using a driverless mobility for patients with musculoskeletal disorders: preliminary clinical study to achieve mobility as a service in medical care.

BACKGROUND: Recent advancements in and the proliferation of autonomous mobility technology, such as intelligent wheelchairs, have made it possible to provide mobility services for patients with reduced mobility due to musculoskeletal disorders. In the present study, we conducted a preliminary clinical study to assess the safety and feasibility of in-hospital autonomous transportation using a driverless mobility (wheelchair) for patients with musculoskeletal disorders. METHODS: From January to February 2022, 51 patients with musculoskeletal disorders exhibiting gait disturbance who presented to our institution were included in the present study. Driverless mobility rides were conducted over a straight-line distance of 100 m from the orthopaedic outpatient reception to the payment counter after the outpatient consultation. We assessed the quality of life using an EQ-5D-5 L index and pain using a VAS score before riding the mobility to investigate the patient's condition. After the ride, a questionnaire survey was conducted to assess patient satisfaction on a 5-point scale. In addition, adverse events during the mobility ride were investigated. RESULTS: Overall satisfaction levels showed that 44 out of 51 (86%) patients rated the level as 3 or higher. There were no significant differences in the level of satisfaction based on the cause of disorders or EQ-5D-5 L Index. Among 19 patients who rated the level of satisfaction as 2-3, the ratio of postoperative patients and those with pain tended to be higher (p < 0.05). While 26 of 51 (51%) patients reported moments of feeling unsafe during the mobility ride, no actual adverse events, such as collisions, were observed. CONCLUSIONS: An in-hospital autonomous transportation service using a driverless mobility for patients with musculoskeletal disorders demonstrated high satisfaction levels and was safe with no severe adverse events observed. The expansion of autonomous mobility deployment is expected to achieve mobility as a service in medical care.

The effectiveness of instrument-assisted soft tissue mobilization on range of motion: a meta-analysis.

BACKGROUND: To evaluate the effectiveness of instrument-assisted soft tissue mobilization (IASTM) on range of motion (ROM). METHODS: We performed a literature search of the PubMed, Embase, Web of Science, and Cochrane Library databases from inception to December 23, 2023. Randomized controlled trials that compared treatment groups receiving IASTM to controls or IASTM plus another treatment(s) to other treatment(s) among healthy individuals with or without ROM deficits, or patients with musculoskeletal disorders were included. The Cochrane risk of bias tool was used to assess the risk of bias. RESULTS: Nine trials including 450 participants were included in the quantitative analysis. The IASTM was effective in improving ROM in degree in healthy individuals with ROM deficits and patients with musculoskeletal disorders (n=4) (MD = 4.94, 95% CI: 3.29 to 6.60), and in healthy individuals without ROM deficits (n=4) (MD = 2.32, 95% CI: 1.30 to 3.34), but failed to improve ROM in centimeter in healthy individuals with ROM deficits (n=1) (MD = 0.39, 95% CI: -1.34 to 2.11, p=0.66, I2 = 88%). CONCLUSIONS: IASTM can improve ROM in degree in healthy individuals with or without ROM deficits, or in patients with musculoskeletal disorders (with very low to low certainty). TRIAL REGISTRATION: The PROSPERO registration ID is CRD42023425200.

Hepatocellular carcinoma and musculoskeletal system: A narrative literature review.

Musculoskeletal alterations in hepatocellular carcinoma (HCC) are less common than liver-related complications. However, they can significantly impact the quality of life and overall prognosis of patients with HCC. The main obstacle in the clinical assessment of HCC-induced musculoskeletal alterations is related to effective and timely diagnosis because these complications are often asymptomatic and unapparent during routine clinical evaluations. This narrative literature review aimed to provide a comprehensive overview of the contemporary literature related to the changes in the musculoskeletal system in patients with HCC, focusing on its clinical implications and underlying etiopathogenetic mechanisms. Osteolytic bone metastases are the most common skeletal alterations associated with HCC, which could be associated with an increased risk of low-trauma bone fracture. Moreover, previous studies reported that osteopenia, sarcopenia, and myosteatosis are associated with poor clinical outcomes in patients with HCC. Even though low bone mineral density and sarcopenia are consistently reported as reliable predictors of pretransplantation and post-transplantation mortality in HCC patients, these complications are frequently overlooked in the clinical management of patients with HCC. Taken together, contemporary literature suggests that a multidisciplinary approach is essential for early recognition and clinical management of HCC-associated musculoskeletal alterations to improve patient prognosis. Further research into the mechanisms and treatment options for musculoskeletal complications is warranted to enhance our understanding and clinical management of this aspect of HCC.

A perspective on muscle phenotyping in musculoskeletal research.

Musculoskeletal research should synergistically investigate bone and muscle to inform approaches for maintaining mobility and to avoid bone fractures. The relationship between sarcopenia and osteoporosis, integrated in the term 'osteosarcopenia', is underscored by the close association shown between these two conditions in many studies, whereby one entity emerges as a predictor of the other. In a recent workshop of Working Group (WG) 2 of the EU Cooperation in Science and Technology (COST) Action 'Genomics of MusculoSkeletal traits Translational Network' (GEMSTONE) consortium (CA18139), muscle characterization was highlighted as being important, but currently under-recognized in the musculoskeletal field. Here, we summarize the opinions of the Consortium and research questions around translational and clinical musculoskeletal research, discussing muscle phenotyping in human experimental research and in two animal models: zebrafish and mouse.

Responsiveness of Subjective and Objective Measures of Pain and Function Following Operative Interventions for Musculoskeletal Conditions: A Narrative Review.

OBJECTIVE: Musculoskeletal (MSK) disorders affect ~50% of US adults and 75% of those over the age of 65, representing a sizable economic and disability burden. Outcome measures, both objective and subjective, help clinicians and investigators determine whether interventions to treat MSK conditions are effective. This narrative review qualitatively compared the responsiveness of different types of outcome measures, a key measurement characteristic that assesses an outcome measure's ability to detect change in patient status. METHODS: We evaluated elective orthopedic interventions as a model for assessing responsiveness because the great majority of patients improves following surgery. We searched for articles reporting responsiveness (quantified as effect size [ES]) of subjective and objective outcome measures after orthopedic surgery and included 16 articles reporting 17 interventions in this review. RESULTS: In 14 of 17 interventions, subjective function measures had an ES 10% greater than that of objective function measures. Two reported a difference in ES of <10%. The sole intervention that demonstrated higher ES of objective function used a composite measure. Sixteen interventions reported measures of subjective pain and/or mixed measures and subjective function. In nine interventions, subjective pain had a higher ES than subjective function by >10%, in three, subjective function had a higher ES than subjective pain by >10%, and in the remaining four, the difference between pain and function was <10%. CONCLUSION: These findings reinforce the clinical observation that subjective pain generally changes more than function following elective orthopedic surgery. They also suggest that subjective function measures are more responsive than objective function measures, and composite scores may be more responsive than individual performance tests.

Exploring the role of task on kinematic variability and assessing consistency in individual responses across repetitive manual tasks.

To gain a greater understanding of motor variability (MV) as an individual trait, the effect of task type on MV and individual consistency in MV across three tasks was investigated. Twenty participants performed repetitive carrying, lifting, and simulated sawing tasks. MV was assessed using the linear measure of mean point-by-point standard deviation in three-dimensional upper body joint angles. Task type affected MV, where carrying showed higher MV compared to sawing (23-29%) and lifting (12-19%). Furthermore, MV was higher in lifting compared to sawing (12-25%). Poor to moderate individual consistency (ICC = 0.42-0.63) was found across tasks. Task type determined MV and only some support for MV as an individual trait across tasks was found. Based on this work, differences in degrees of freedom afforded by the task influence the opportunity to exploit MV, and possibly individual consistency in MV magnitude is specific to the degrees of freedom afforded by the task. Practitioner summary: In repetitive tasks, movement variability has been proposed as an individual characteristic independent of task characteristics, where repeaters show consistently low variability, while replacers show consistently high variability. In the current study, only moderate support was demonstrated for variability as a consistent individual characteristic across different manual tasks.AbbreviationMV: Motor variability; WRMSDs: Work-related musculoskeletal disorders; DOF: Degrees of freedom; meanSD: Mean standard deviation; SD: Standard deviation; H: Handle (of simulated sawing setup); T: Track (of simulated sawing setup); F: Frame (of simulated sawing setup); ICC: Intraclass correlation; UE: Upper extremity; MMH: Manual material handling; EMG: Electromyography.

Lifting capacity prediction model using physical performance measures among construction workers.

Manual materials handling is performed in many workplaces and is a significant risk factor for musculoskeletal injuries. The identification of lifting capacity is important to reduce the occurrence of musculoskeletal injuries. Lifting capacity is difficult to evaluate at the workplace. Therefore, there is a need to develop an alternate method that is easy and could be performed at the workplace. The study aimed to develop a lifting capacity prediction model for construction workers based on muscle strength and endurance. In this study, 65 construction workers were recruited; their socio-demographic and physical characteristics like core strength and endurance, grip strength, and lower limb flexibility were assessed. The lifting capacity was assessed using progressive isoinertial lifting evaluation. Stepwise multiple linear regression was carried out to develop the prediction model. The study suggested that age, BMI, grip strength, flexibility, prone plank, and trunk lateral flexor endurance tests have significantly influenced lifting capacity. Hence prediction model is developed using these variables. The regression model developed would help in easy estimation of lifting capacity among construction workers, which could be even administered with minimal skills by site supervisors or managers. It might help in the decision-making during pre-placement or return to work evaluations, thereby minimizing the incidence of low back disorders.

ADSC-Based Cell Therapies for Musculoskeletal Disorders: A Review of Recent Clinical Trials.

Recently published clinical trials involving the use of adipose-derived stem cells (ADSCs) indicated that approximately one-third of the studies were conducted on musculoskeletal disorders (MSD). MSD refers to a wide range of degenerative conditions of joints, bones, and muscles, and these conditions are the most common causes of chronic disability worldwide, being a major burden to the society. Conventional treatment modalities for MSD are not sufficient to correct the underlying structural abnormalities. Hence, ADSC-based cell therapies are being tested as a form of alternative, yet more effective, therapies in the management of MSDs. Therefore, in this review, MSDs subjected to the ADSC-based therapy were further categorized as arthritis, craniomaxillofacial defects, tendon/ligament related disorders, and spine disorders, and their brief characterization as well as the corresponding conventional therapeutic approaches with possible mechanisms with which ADSCs produce regenerative effects in disease-specific microenvironments were discussed to provide an overview of under which circumstances and on what bases the ADSC-based cell therapy was implemented. Providing an overview of the current status of ADSC-based cell therapy on MSDs can help to develop better and optimized strategies of ADSC-based therapeutics for MSDs as well as help to find novel clinical applications of ADSCs in the near future.

Observational study of an inpatient program for musculoskeletal disorders: The effects of gender and physical activity.

ABSTRACT: A new inpatient secondary preventive program for patients with musculoskeletal health problems was introduced throughout Austria. The aim of the current work was to evaluate this "Health Prevention Active" program and its possible influences on the quality of medical results upon hospital discharge.This observational study presents monocentric data for 7448 patients (48.99 ±â€Š6.15 years; 53.7% women) with chronic musculoskeletal disorders who completed a 3-week health program. The focus was placed on measuring medical quality outcomes such as BMI, blood pressure, heart rate, pain, subjective ratings, and achieved power output in cycle ergometer exercise testing. We describe pre-post changes before and after the inpatient program and the results of a follow-up survey conducted after 1 year to identify moderating factors related to health outcomes.The medical baseline showed obvious deficits regarding obesity, hypertension, and subjective symptoms. Of all patients, 36.5% were completely inactive. The patient's gender and physical activity had a high impact on the medical baseline status. In total, the majority of patients (86.2%; SMD = -0.78 ±â€Š0.59) responded well to the health prevention program, independent of their ages and lifestyles.Requirements for secondary prevention programs are high. The results of the study reflect the general problems presented by inactivity, obesity, and subjective symptoms like pain. Physical activity was specifically identified as a major factor for the observed medical baseline status.

Pathogenesis of Musculoskeletal Deficits in Children and Adults with Inflammatory Bowel Disease.

Musculoskeletal deficits are among the most commonly reported extra-intestinal manifestations and complications of inflammatory bowel disease (IBD), especially in those with Crohn's disease. The adverse effects of IBD on bone and muscle are multifactorial, including the direct effects of underlying inflammatory disease processes, nutritional deficits, and therapeutic effects. These factors also indirectly impact bone and muscle by interfering with regulatory pathways. Resultantly, individuals with IBD are at increased risk of osteoporosis and sarcopenia and associated musculoskeletal morbidity. In paediatric IBD, these factors may contribute to suboptimal bone and muscle accrual. This review evaluates the main pathogenic factors associated with musculoskeletal deficits in children and adults with IBD and summarises the current literature and understanding of the musculoskeletal phenotype in these patients.

Neck pain associated with migraine does not necessarily reflect cervical musculoskeletal dysfunction.

OBJECTIVE: To identify how frequently the neck pain associated with migraine presents with a pattern of cervical musculoskeletal dysfunction akin to cervical musculoskeletal disorders, and to determine if pain hypersensitivity impacts on cervical musculoskeletal function in persons with migraine. BACKGROUND: Many persons with migraine experience neck pain and often seek local treatment. Yet neck pain may be part of migraine symptomology and not from a local cervical source. If neck pain is of cervical origin, a pattern of musculoskeletal impairments with characteristics similar to idiopathic neck pain should be present. Some individuals with migraine may have neck pain of cervical origin, whereas others may not. However, previous studies have neglected the disparity in potential origins of neck pain and treated persons with migraine as a homogenous group, which does not assist in identifying the origin of neck pain in individuals with migraine. METHODS: This cross-sectional, single-blinded study was conducted in a research laboratory at the University of Queensland, Australia. Persons with migraine (total n = 124: episodic migraine n = 106, chronic migraine = 18), healthy controls (n = 32), and persons with idiopathic neck pain (n = 21) were assessed using a set of measures typically used in the assessment of a cervical musculoskeletal disorder, including cervical movement range and accuracy, segmental joint dysfunction, neuromuscular and sensorimotor measures. Pain hypersensitivity was assessed using pressure pain thresholds and the Allodynia Symptom Checklist. People with migraine with diagnoses of comorbid neck disorders were excluded. Cluster analysis was performed to identify how participants grouped on the basis of their performance across cervical musculoskeletal assessments. Post hoc analyses examined the effects of pain hypersensitivity on musculoskeletal function, and if any symptoms experienced during testing were related to musculoskeletal function. RESULTS: Two distinct clusters of cervical musculoskeletal function were found: (i) neck function similar to healthy controls (n = 108) and (ii) neck dysfunction similar to persons with neck pain disorders (n = 69). Seventy-six of the individuals with migraine (62 with neck pain and 14 without neck pain) were clustered as having normal cervical musculoskeletal function, whereas the remaining 48 with neck pain had cervical dysfunction comparable with a neck disorder. Musculoskeletal dysfunction was not related to pain hypersensitivity or symptoms experienced during testing. CONCLUSIONS: Neck pain when present with migraine does not necessarily indicate the existence of cervical musculoskeletal dysfunction. Skilled assessment without reliance only on the person reporting symptoms is needed to identify actual cervical dysfunction. Treatments suitable for neck musculoskeletal disorders would seem inappropriate for the individuals without cervical dysfunction. Future studies evaluating any potential effects of such treatments should only select participants with neck pain of cervical origin.

The Conundrum of Kappa and Why Some Musculoskeletal Tests Appear Unreliable Despite High Agreement: A Comparison of Cohen Kappa and Gwet AC to Assess Observer Agreement When Using Nominal and Ordinal Data.

In clinical practice, physical therapists often use different kinds of tests and measures in the assessment of their patients. For therapists to have confidence when using their tests and measures, an important attribute is having intratester and intertester reliability. Studies that assess reliability are cases of observer agreement. Many studies have been performed assessing observer agreement in the physical therapy literature. The most commonly used method to assess observer agreement studies that use nominal or ordinal data is the statistical method suggested by Cohen and the corresponding reliability coefficient, Cohen kappa. Recently, Cohen kappa has undergone scrutiny because of what is called kappa paradox, which occurs when observer agreement is high but the resulting kappa value is low. Another paradox also occurs when asymmetries exist between raters on their disagreements, resulting in a higher kappa value. In the physical therapy literature, there are numerous examples of this problem, which can often lead to misunderstanding the meaning of the data. This Perspective examines how and why these problems occur and suggests an alternative method for assessing observer agreement.

Feasibility of a home-based foot-ankle exercise programme for musculoskeletal dysfunctions in people with diabetes: randomised controlled FOotCAre (FOCA) Trial II.

This study sought to assess the feasibility of design, adherence, satisfaction, safety and changes in outcomes followed by a home-based foot-ankle exercise guided by a booklet in individuals with diabetic peripheral neuropathy (DPN). 20 participants were allocated usual care [control group (CG)] or usual care plus home-based foot-ankle exercises [intervention group (IG)] for 8 weeks. For feasibility, we assessed contact, preliminary screening and recruitment rates, adherence, and using a 5-point Likert scale to satisfaction and safety of the booklet. In the IG, we assessed preliminary changes in DPN symptoms, DPN severity (classified by a fuzzy model) and foot-ankle range of motion between baseline and Week 8. In the first 20 weeks, 1310 individuals were screened for eligibility by phone contact. Contact rate was 89% (contacted participants/20w), preliminary screening success 28% (participants underwent screening/20w), and recruitment rate 1.0 participants/week (eligible participants/20w). The recruitment rate was less than the ideal rate of 5 participants/week. The adherence to the exercises programme was 77%, and the dropout was 11% and 9% for the IG and CG, respectively. In the IG, participants' median level of satisfaction was 4 (IQR: 4-5) and perceived safety was 3 (IQR: 3-5). IG significantly decreased the DPN severity (p = 0.020), increased hallux relative to forefoot (first metatarsal) range of motion (ROM) (p < 0.001) and decreased maximum forefoot relative to hindfoot (midfoot motion) dorsiflexion during gait (p = 0.029). The home-based programme was feasible, satisfactory, safe and showed preliminary positive changes in DPN severity and foot motion during gait.Trial Registration ClinicalTrials.gov, NCT04008745. Registered 02/07/2019. https://clinicaltrials.gov/ct2/show/NCT04008745 .

Bibliometric Analysis of the English Musculoskeletal Literature over the Last 30 Years.

Publication and authorship are important in academia for career advancement, obtaining grants, and improved patient care. There has been a recent interest in bibliometric changes over time, especially regarding the gender gap. The purpose of this study was to explore bibliometric changes in the musculoskeletal literature. Bibliometric variables (number of authors, institutions, countries, pages, references, corresponding author position, author gender, geographic region of origin, and editorial board makeup) were analyzed for 5 basic science and 12 clinically oriented musculoskeletal journals from 1985 through 2016. Statistical analyses comprised bivariate analyses, multifactorial ANOVAs, and logistic regression analyses. A p < 0.005 was considered significant. Nearly, all variables increased over time. Asia had the highest number of authors and corresponding author positions, Australia/New Zealand the highest number of institutions and references, North America the highest number of pages, and Europe the highest number of countries. Those with a female first author had more authors, institutions, countries, references, and pages. Likewise, those with a female corresponding author had more authors, institutions, countries, references, and pages. Single-authored manuscripts decreased over time. The percentage of female first authors rose from 10.8% in 1985-1987 to 23.7% in 2015-2016. There were more female 1st authors in the basic science journals compared to the clinical journals (33.2% vs. 12.7%). Single-authored manuscripts were more likely to be written by males (5.1 vs. 2.4%) and decreased over time. The many differences by geographic region of origin likely reflect different socio/cultural attitudes regarding academia and research, as well as the gender composition of the disciplines by geographic region. Overall, there has been an increase in the number of female 1st and corresponding authors, editorial board members, and chief editors, indicating a slow but progressive narrowing of the gender gap.

Left/right discrimination is not impaired in people with unilateral chronic Achilles tendinopathy.

OBJECTIVE: Impaired left/right discrimination of an affected body part has been observed in various chronic pain states. This study aimed to examine whether people with unilateral chronic Achilles tendinopathy also present with impaired left/right discrimination. DESIGN: Cross-sectional study. METHODS: Nineteen runners with persistent unilateral Achilles tendinopathy and 19 matched healthy volunteers performed a left/right discrimination task in a laboratory setting. Participants were shown pictures of feet, hands and Shepard-Metzler figures and were asked to decide as accurately and as fast as possible whether the body part belonged to the left or right side of the body, or whether the Shepard-Metzler figures were rotated or mirrored. Performance was evaluated in terms of accuracy and response time. Data were analysed with mixed-design ANOVAs. RESULTS: The decline in left/right discrimination ability at group level, if present, between affected and unaffected side, or compared to healthy participants, was negligible for both accuracy (<1.5%) and response time (<50 ms). There was no significant effect of side (affected versus unaffected side) or group (people with Achilles tendinopathy versus healthy) for accuracy (p > 0.36) or response time (p > 0.69). CONCLUSIONS: People with Achilles tendinopathy recognised the affected side as accurately and as fast as the non-affected side and their performance was comparable to healthy participants. The absence of impaired left/right discrimination despite the chronicity of the condition may be attributable to the typical intermittent nature of Achilles tendinopathy pain and/or maintained sports activity.

The effects of spaceflight microgravity on the musculoskeletal system of humans and animals, with an emphasis on exercise as a countermeasure: a systematic scoping review.

The purpose of this systematic review is twofold: 1) to identify, evaluate, and synthesize the heretofore disparate scientific literatures regarding the effects of direct exposure to microgravity on the musculoskeletal system, taking into account for the first time both bone and muscle systems of both humans and animals; and 2) to investigate the efficacy and limitations of exercise countermeasures on the musculoskeletal system under microgravity in humans.The Framework for Scoping Studies (Arksey and O'Malley 2005) and the Cochrane Handbook for Systematic Reviews of Interventions (Higgins JPT 2011) were used to guide this review. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist was utilized in obtaining the combined results (Moher, Liberati et al. 2009). Data sources, PubMed, Embase, Scopus, and Web of Science were searched for published articles through October 2019 using the Mesh terms of microgravity, musculoskeletal system, and exercise countermeasures. A total of 84 references were selected, including 40 animal studies and 44 studies with human participants. The heterogeneity in the study designs, methodologies, and outcomes deemed this review unsuitable for a meta-analysis. Thus, we present a narrative synthesis of the results for the key domains under five categories: 1) Skeletal muscle responses to microgravity in humans 2) Skeletal muscle responses to microgravity in animals 3) Adaptation of the skeletal system to microgravity in humans 4) Adaptation of the skeletal system to microgravity in animals 5) Effectiveness of exercise countermeasures on the human musculoskeletal system in microgravity. Existing studies have produced only limited data on the combined effects on bone and muscle of human spaceflight, despite the likelihood that the effects on these two systems are complicated due to the components of the musculoskeletal system being anatomically and functionally interconnected. Bone is directly affected by muscle atrophy as well as by changes in muscle strength, notably at muscle attachments. Given this interplay, the most effective exercise countermeasure is likely to be robust, individualized, resistive exercise, primarily targeting muscle mass and strength.