Unsupervised machine learning for clustering forward head posture, protraction and retraction movement patterns based on craniocervical angle data in individuals with nonspecific neck pain.

OBJECTIVES: The traditional understanding of craniocervical alignment emphasizes specific anatomical landmarks. However, recent research has challenged the reliance on forward head posture as the primary diagnostic criterion for neck pain. An advanced relationship exists between neck pain and craniocervical alignment, which requires a deeper exploration of diverse postures and movement patterns using advanced techniques, such as clustering analysis. We aimed to explore the complex relationship between craniocervical alignment, and neck pain and to categorize alignment patterns in individuals with nonspecific neck pain using the K-means algorithm. METHODS: This study included 229 office workers with nonspecific neck pain who applied unsupervised machine learning techniques. The craniocervical angles (CCA) during rest, protraction, and retraction were measured using two-dimensional video analysis, and neck pain severity was assessed using the Northwick Park Neck Pain Questionnaire (NPQ). CCA during sitting upright in a comfortable position was assessed to evaluate the resting CCA. The average of midpoints between repeated protraction and retraction measures was considered as the midpoint CCA. The K-means algorithm helped categorize participants into alignment clusters based on age, sex and CCA data. RESULTS: We found no significant correlation between NPQ scores and CCA data, challenging the traditional understanding of neck pain and alignment. We observed a significant difference in age (F = 140.14, p < 0.001), NPQ total score (F = 115.83, p < 0.001), resting CCA (F = 79.22, p < 0.001), CCA during protraction (F = 33.98, p < 0.001), CCA during retraction (F = 40.40, p < 0.001), and midpoint CCA (F = 66.92, p < 0.001) among the three clusters and healthy controls. Cluster 1 was characterized by the lowest resting and midpoint CCA, and CCA during pro- and -retraction, indicating a significant forward head posture and a pattern of retraction restriction. Cluster 2, the oldest group, showed CCA measurements similar to healthy controls, yet reported the highest NPQ scores. Cluster 3 exhibited the highest CCA during protraction and retraction, suggesting a limitation in protraction movement. DISCUSSION: Analyzing 229 office workers, three distinct alignment patterns were identified, each with unique postural characteristics; therefore, treatments addressing posture should be individualized and not generalized across the population.

Comparison of acromiohumeral distance and glenohumeral internal rotation angle between the empty can test and modified empty can test: "thumb pointing down" versus "elbow pointing laterally".

BACKGROUND: During the empty can test, the direction of the thumb (downward) has been widely used as an instruction for producing glenohumeral internal rotation. However, the combination of forearm pronation and thumb motion as a compensatory movement could contribute to the lack of glenohumeral internal rotation during the empty can test. This study aimed to compare the glenohumeral internal rotation angle between the conventional empty can (with thumb direction) and modified empty can tests (with elbow direction), as well as the acromiohumeral distance between the full can, conventional empty can, and modified empty can tests. METHODS: In this laboratory study, we measured the glenohumeral internal rotation angle using a motion sensor and the acromiohumeral distance using ultrasonography during the following tests: full can test (thumb pointing up), conventional empty can test (thumb pointing down), and modified empty can test (elbow pointing laterally) in 20 healthy subjects. RESULTS: Compared with the conventional empty can test, the glenohumeral internal rotation angle was significantly greater during the modified empty can test (p < 0.05). Furthermore, the acromiohumeral distance measured in the modified empty can test was significantly less than that in the full can test (p < 0.001) and conventional empty can test (p < 0.001). However, there was no difference in the acromiohumeral distance between the full can test and the conventional empty can test (p > 0.017). CONCLUSIONS: During the empty can test, the instructions should be given to patients based on the elbow direction (elbow pointing laterally). The modified empty can test can produce full glenohumeral internal rotation, compared with instructions based on the thumb direction (thumb pointing down). Consequently, the modified empty can test can produce a more decreased subacromial space.

Prediction model of subacromial pain syndrome in assembly workers using shoulder range of motion and muscle strength based on support vector machine.

Subacromial pain syndrome (SAPS) is the most common upper-extremity musculoskeletal problem among workers. In this study, a machine learning model was built to predict and classify the presence or absence of SAPS in assembly workers with shoulder joint range of motion (ROM) and muscle strength data using support vector machine (SVM). Permutation importance was used to determine important variables for predicting workers with or without SAPS. The accuracy of the support vector classifier (SVC) polynomial model for classifying workers with SAPS was 82.4%. The important variables in model construction were internal rotation and abduction of shoulder ROM and internal rotation of shoulder muscle strength. It is possible to accurately perform SAPS classification of workers with relatively easy-to-obtain shoulder ROM and muscle strength data using this model. In addition, preventing SAPS in workers is possible by adjusting the factors affecting model building using exercise or rehabilitation programs.Practitioner summary: This study aimed to create a machine learning model that can predict and classify SAPS using shoulder ROM and muscle strength and identify the variables that are of high importance in model construction. This model could be used to predict or classify workers' SAPS and manage or prevent SAPS.

Dealkenylative Alkynylation Using Catalytic FeII and Vitamin C.

In this paper, we report the synthesis of alkyl-tethered alkynes through ozone-mediated and FeII-catalyzed dealkenylative alkynylation of unactivated alkenes in the presence of alkynyl sulfones. This one-pot reaction, which employs a combination of a catalytic FeII salt and l-ascorbic acid, proceeds under mild conditions with good efficiency, high stereoselectivity, and broad functional group compatibility. In contrast to our previous FeII-mediated reductive fragmentation of α-methoxyhydroperoxides, the FeII-catalyzed process was devised through a thorough kinetic analysis of the multiple competing radical (redox) pathways. We highlight the potential of this dealkenylative alkynylation through multiple post-synthetic transformations and late-stage diversifications of complex molecules, including natural products and pharmaceuticals.

Enantioselective Synthesis of Quaternary Oxindoles: Desymmetrizing Staudinger-Aza-Wittig Reaction Enabled by a Bespoke HypPhos Oxide Catalyst.

This paper describes a catalytic asymmetric Staudinger-aza-Wittig reaction of (o-azidoaryl)malonates, allowing access to chiral quaternary oxindoles through phosphine oxide catalysis. We designed a novel HypPhos oxide catalyst to enable the desymmetrizing Staudinger-aza-Wittig reaction through the PIII/PV═O redox cycle in the presence of a silane reductant and an IrI-based Lewis acid. The reaction occurs under mild conditions, with good functional group tolerance, a wide substrate scope, and excellent enantioselectivity. Density functional theory revealed that the enantioselectivity in the desymmetrizing reaction arose from the cooperative effects of the IrI species and the HypPhos catalyst. The utility of this methodology is demonstrated by the (formal) syntheses of seven alkaloid targets: (-)-gliocladin C, (-)-coerulescine, (-)-horsfiline, (+)-deoxyeseroline, (+)-esermethole, (+)-physostigmine, and (+)-physovenine.

Altered muscle recruitment patterns during isometric shoulder abduction in individuals with chronic upper trapezius pain: a cross sectional study.

BACKGROUND: Upper trapezius (UT) pain with myofascial trigger points (MTrPs) can affect movement at the glenohumeral joint as well as at the scapulothoracic joint. The investigation of muscle recruitment patterns can discern motor control strategies. The purpose of this study was to compare shoulder muscle recruitment patterns and muscle activity according to various loads between individuals with and without chronic UT pain. METHODS: In this cross-sectional study, twenty-four participants that had UT pain with MTrPs and sex, age, body weight matched 24 controls with no UT pain were recruited. Surface EMG electrodes were attached to the UT, the serratus anterior (SA), the lower trapezius (LT) and the middle deltoid (MD). All participants performed isometric shoulder abduction with a load of 25%, 50%, or 75% of the maximum strength at 60° of shoulder abduction. The EMG activity, the activity ratio (SA/UT, LT/UT, MD/UT), and the relative contribution of each muscle activity were calculated. RESULTS: MD activity was significantly decreased in the UT pain group compared to that in the control group (p < 0.05). The EMG activity ratio of SA/UT (p < 0.025) and the relative contribution of SA activity to shoulder abduction (p < 0.05) were significantly greater in the UT pain group than in the control group in the 25% loading condition. CONCLUSION: The results of present study showed that UT pain with MTrPs may increase the relative contribution of SA activity and decrease MD activity at low loads. Altered recruitment patterns of scapular upward rotators can be altered in the proper scapular position, which results in decreased MD activity. Clinicians should consider altered recruitment patterns when managing UT pain. TRIAL REGISTRATION: Clinical Research Information Service: Clinical Research Information Service (KCT0007370; 08/06/2022).

Subgrouping of Peripheral Neuropathic Pain Patients According to Sensory Symptom Profile Using the Korean Version of the PainDETECT Questionnaire.

BACKGROUND: A culturally validated Korean version of the PainDETECT Questionnaire (PD-Q) was used to identify neuropathic pain components (NeP) in patients suffering from chronic pain. The purpose of this study was to determine if the Korean PD-Q can be used to subgroup patients with peripheral NeP according to sensory symptom profiles. METHODS: This study included 400 Korean patients with peripheral neuropathic pain diagnosed as probable or definite NeP. The total scores and subscores for each item in PD-Q were transformed into a Z-score for standardization. Hierarchical cluster analysis was performed to identify clusters of subjects by PD-Q scores. RESULTS: The mean total PD-Q score of the study participants was 14.57 ± 6.46. A hierarchical cluster analysis identified 5 clusters with distinct pain characteristic profiles. Cluster 1 had relatively severe burning and tingling sensations. The mean total PD-Q score for cluster 2 was the lowest of the 5 clusters. Cluster 3 tended to be vulnerable to pain in response to cold/heat stimulation. Cluster 4 showed relatively severe pain induced by physical stimuli, such as light touch or slight pressure. Cluster 5 had high scores for all NeP symptoms. CONCLUSION: This study demonstrates the ability of patients to cluster by symptoms using the Korean PD-Q. Subgrouping of peripheral neuropathic pain by sensory symptom profile may be useful in making effective drug treatment decisions.

Comparison of MOG and AQP4 antibody seroprevalence in Korean adults with inflammatory demyelinating CNS diseases.

We aimed to compare seroprevalence of anti-myelin oligodendrocyte glycoprotein (MOG) and anti-aquaporin-4 (AQP4) antibodies in Korean adults with inflammatory demyelinating diseases (IDDs) of the central nervous system (CNS), based on a multicenter nationwide database. Sera were analyzed using a live cell-based assay for MOG and AQP4 antibodies. Of 586 Korean adults with IDDs of the CNS, 36 (6.1%) and 185 (31.6%) tested positive for MOG and AQP4 antibodies, respectively. No participant showed double positivity. Seroprevalence of MOG antibodies was about five times lower than that of AQP4 antibodies in a large cohort of Korean adults with IDDs of the CNS.

Correlation between 3D scanner image and MRI for tracking volume changes in head and neck cancer patients.

INTRODUCTION: We investigated the correlation between optical surface imaging using a three-dimensional (3D) scanner and magnetic resonance imaging (MRI) for suggesting feasibility in the clinical process of tracking volume changes in head and neck patients during radiation treatment. METHODS: Ten patients were divided into two groups depending on the location of their tumor (i.e., right or left side). With weekly imaging data, the change in volume based on MRI was evaluated during the treatment course. Four volumes of interest (VOIs) were calculated on the 3D surface image of the facial and cervical areas using an optical 3D scanner, and the correlation between volumetric parameters were analyzed. RESULTS: The target volume changed significantly overall for both groups. The changes parotid volume reduced by up to 3.8% and 28.0% for groups A (right side) and B (left side), respectively. In Group A, VOI 1 on the facial area and VOI 3 on the cervical area decreased gradually during the treatment course by up to 3.3% and 10.7%, respectively. In Group B, only VOI 4 decreased gradually during the treatment course and reduced by up to 9.2%. In group A, the change in target volume correlated strongly with right-side parotid, VOI 1, and VOI 3, respectively. The parotid also showed strong correlations with VOIs (P < 0.01). The weight loss was strongly correlated with either PTV or parotid without statistical significance (P > 0.05). In group B (left side), the change in target volume correlated strongly with each volumetric parameter, including weight loss. For individual patient, PTV showed more correlation with VOIs on the cervical area than VOIs on the facial area. CONCLUSIONS: An optical 3D scanner can be applied to track changes in volume without radiation exposure during treatment and the optical surface image correlated with MRI.

Comparison of the Shoulder External Rotator Strength and Asymmetry Ratio Between Workers With and Without Shoulder Impingement Syndrome.

ABSTRACT: Kim, J-H, Kwon, O-Y, Hwang, U-J, Jung, S-H, Ahn, S-H, and Kim, H-A. Comparison of shoulder external rotator strength and the asymmetry ratio between workers with and without shoulder impingement syndrome. J Strength Cond Res 35(12): 3364-3369, 2021-Shoulder impingement syndrome (SIS) is the most common shoulder problem causing shoulder pain. Several studies have indicated that shoulder external rotator muscles provide dynamic stability to the shoulder joint. However, the relationship of SIS to changes in shoulder external rotator muscle strength remains controversial. The purpose of the study was to compare the shoulder external rotator strength and asymmetry ratio between workers with SIS and the normal group in a side-lying position. Twelve male industrial workers with SIS and the normal group of 12 workers participated in this study. A pulling sensor measured shoulder external rotator muscle strength in a side-lying position with the shoulder at 0° and 90° of flexion. The asymmetry ratio was calculated by a specific formula using the shoulder external rotator muscle strength of the dominant side and the unaffected side. Two-way analysis of variance was used to determine between-group differences in shoulder external rotator muscle strength and the asymmetry ratio among the 2 positions. Subjects with SIS did not exhibit significant differences in shoulder external rotator muscle strength in the side-lying position with the shoulder at 0° and 90° of flexion relative to the normal group. However, subjects with SIS had a significantly increased asymmetry ratio of shoulder external rotation strength in the side-lying position with the shoulder at 90° of flexion compared with the normal group. In conclusion, workers with SIS had an asymmetry of shoulder external rotator strength in side-lying with the shoulder at 90° of flexion.

Electromyographic Analysis of Hip and Trunk Muscle Activity During Side Bridge Exercises in Subjects With Gluteus Medius Weakness.

CONTEXT: Side bridge exercises strengthen the hip, trunk, and abdominal muscles and challenge the trunk muscles without the high lumbar compression associated with trunk extension or curls. Previous research using electromyography (EMG) reports that performance of the side bridge exercise highly activates the gluteus medius (Gmed). However, to the best of our knowledge, no previous research has investigated EMG amplitude in the hip and trunk muscles during side bridge exercise in subjects with Gmed weakness. OBJECTIVE: The purpose of this study was to examine the EMG activity of the hip and trunk muscles during 3 variations of the side bridge exercise (side bridge, side bridge with knee flexion, and side bridge with knee flexion and hip abduction of the top leg) in subjects with Gmed weakness. DESIGN: Repeated-measures experimental design. SETTING: Research laboratory. PATIENTS: Thirty subjects (15 females and 15 males) with Gmed weakness participated in this study. INTERVENTION: Each subject performed 3 variations of the side bridge exercise in random order. MAIN OUTCOME MEASURES: Surface EMG was used to measure the muscle activities of the rectus abdominis, external oblique, longissimus thoracis, multifidus, Gmed, gluteus maximus, and tensor fasciae latae (TFL), and Gmed/TFL muscle activity ratio during 3 variations of the side bridge exercise. RESULTS: There were significant differences in Gmed (F2,56 = 110.054, P < .001), gluteus maximus (F2,56 = 36.416, P < .001), and TFL (F2,56 = 108.342, P < .001) muscles among the 3 side bridge exercises. There were significant differences in the Gmed/TFL muscle ratio (F2,56 = 20.738, P < .001). CONCLUSION: Among 3 side bridge exercises, the side bridge with knee flexion may be effective for the individuals with Gmed weakness among 3 side bridge exercises to strengthen the gluteal muscles, considering the difficulty of the exercise and relative contribution of Gmed and TFL.

Unified Approach to Furan Natural Products via Phosphine-Palladium Catalysis.

Polyalkyl furans are widespread in nature, often performing important biological roles. Despite a plethora of methods for the synthesis of tetrasubstituted furans, the construction of tetraalkyl furans remains non-trivial. The prevalence of alkyl groups in bioactive furan natural products, combined with the desirable bioactivities of tetraalkyl furans, calls for a general synthetic protocol for polyalkyl furans. This paper describes a Michael-Heck approach, using sequential phosphine-palladium catalysis, for the preparation of various polyalkyl furans from readily available precursors. The versatility of this method is illustrated by the total syntheses of nine distinct polyalkylated furan natural products belonging to different classes, namely the furanoterpenes rosefuran, sesquirosefuran, and mikanifuran; the marine natural products plakorsins A, B, and D and plakorsin D methyl ester; and the furan fatty acids 3D5 and hydromumiamicin.

Two distinct cases with COVID-19 in kidney transplant recipients.

The fatality of novel coronavirus disease 2019 (COVID-19) is precipitously increased in patients with underlying comorbidities or elderly people. Kidney transplant (KT) recipients are one of the vulnerable populations for infection. COVID-19 infection in KT recipients might be a complicated and awkward situation, but there has been a lack of reports concerning this group. Herein, we demonstrated two distinct cases with different clinical progress. The first case was a 36-year-old man who underwent KT 3 years ago. He was diagnosed with COVID-19 expressing relevant symptoms. Following administration of lopinavir/ritonavir and hydroxychloroquine with reduced immunosuppressant, he recovered from COVID-19. However, the unexpected fluctuations in tacrolimus trough levels needed to be managed because of drug-to-drug interaction. The second case was developed in a 56-year-old man without any symptoms. He received a second KT from an ABO-incompatible donor 8 years ago. He was diagnosed with COVID-19 by screening due to exposure history. During the hospitalization period, the chest infiltrative lesion showed a wax and wane, but he successfully recovered by administration of hydroxychloroquine with azithromycin. These apparently different cases suggest that assertive screening and management could improve the clinical course. In addition, antiviral agents should be used cautiously, especially in patients on calcineurin inhibitors.

Phosphine Organocatalysis.

The hallmark of nucleophilic phosphine catalysis is the initial nucleophilic addition of a phosphine to an electrophilic starting material, producing a reactive zwitterionic intermediate, generally under mild conditions. In this Review, we classify nucleophilic phosphine catalysis reactions in terms of their electrophilic components. In the majority of cases, these electrophiles possess carbon-carbon multiple bonds: alkenes (section 2), allenes (section 3), alkynes (section 4), and Morita-Baylis-Hillman (MBH) alcohol derivatives (MBHADs; section 5). Within each of these sections, the reactions are compiled based on the nature of the second starting material-nucleophiles, dinucleophiles, electrophiles, and electrophile-nucleophiles. Nucleophilic phosphine catalysis reactions that occur via the initial addition to starting materials that do not possess carbon-carbon multiple bonds are collated in section 6. Although not catalytic in the phosphine, the formation of ylides through the nucleophilic addition of phosphines to carbon-carbon multiple bond-containing compounds is intimately related to the catalysis and is discussed in section 7. Finally, section 8 compiles miscellaneous topics, including annulations of the Hüisgen zwitterion, phosphine-mediated reductions, iminophosphorane organocatalysis, and catalytic variants of classical phosphine oxide-generating reactions.

Classification-Specific Treatment Improves Pain, Disability, Fear-Avoidance Beliefs, and Erector Spinae Muscle Activity During Walking in Patients With Low Back Pain Exhibiting Lumbar Extension-Rotation Pattern: A Randomized Controlled Trial.

OBJECTIVE: Low back pain (LBP) has commonly been managed via classification-specific interventions in homogeneous groups. However, it is largely unknown whether treatment tailored to specific classifications is more effective than generic treatment. The purpose of this study was to evaluate the effects of classification-specific treatment on the self-reported responses and erector spinae (ES) activity of patients with LBP exhibiting a lumbar extension-rotation (ExtRot) pattern. METHODS: In total, 39 patients exhibiting the lumbar ExtRot pattern were randomized to an experimental (n = 19) group and a control (n = 20) group. Participants in the experimental group received classification-specific treatment, which included exercise to control or prevent lumbopelvic motion during lower-extremity movement. Participants in the control group were encouraged to perform general exercises and were educated about LBP. Patient-reported pain intensity, disability, and fear-avoidance belief and ES muscle activity during walking were assessed prior to and after the intervention. Two-way analysis of covariance was used to examine the effects of classification-specific treatment. RESULTS: After 6-week intervention, significant time-by-group interaction effects were demonstrated on pain intensity, disability, fear-avoidance beliefs-physical activity score, and ES muscle activity during walking. There were significant effects of group on pain, disability, and fear-avoidance beliefs-physical activity score after intervention. After the 6-week intervention, the ES muscle activity significantly decreased in the experimental group during walking, but does not represent an all-events decrease. CONCLUSION: Classification-specific treatment may be effective in patients with LBP exhibiting the lumbar ExtRot pattern, reducing pain intensity, disability, fear-avoidance beliefs, and ES muscle activity during walking.

Effect of Abdominal Electrical Muscle Stimulation Training With and Without Superimposed Voluntary Muscular Contraction on Lumbopelvic Control.

CONTEXT: Electrical muscle stimulation (EMS) was designed for artificial muscle activation or superimposed training. OBJECTIVES: To compare the effects of 8 weeks of superimposed technique (ST; application of electrical stimulation during a voluntary muscle action) and EMS on the cross-sectional area of the rectus abdominis, lateral abdominal wall, and on lumbopelvic control. SETTING: University research laboratory. DESIGN: Randomized controlled trial. PARTICIPANTS: Fifty healthy subjects were recruited and randomly assigned to either the ST or EMS group. INTERVENTION: The participants engaged with the electrical stimulation techniques (ST or EMS) for 8 weeks. MAIN OUTCOME MEASURES: In all participants, the cross-sectional area of the rectus abdominis and lateral abdominal wall was measured by magnetic resonance imaging and lumbopelvic control, quantified using the single-leg and double-leg lowering tests. RESULTS: There were no significant differences in the cross-sectional area of the rectus abdominis (right: P = .70, left: P = .99) or lateral abdominal wall (right: P = .07, left: P = .69) between groups. There was a significant difference between groups in the double-leg lowering test (P = .03), but not in the single-leg lowering test (P = .88). There were significant differences between the preintervention and postintervention in the single-leg (P < .001) and double-leg lowering tests (P < .001). CONCLUSIONS: ST could improve lumbopelvic control in the context of athletic training and fitness.

Dealkenylative Alkenylation: Formal σ-Bond Metathesis of Olefins.

The dealkenylative alkenylation of alkene C(sp3 )-C(sp2 ) bonds has been an unexplored area for C-C bond formation. Herein 64 examples of ß-alkylated styrene derivatives, synthesized through the reactions of readily accessible feedstock olefins with ß-nitrostyrenes by ozone/FeII -mediated radical substitutions, are reported. These reactions proceed with good efficiencies and high stereoselectivities under mild reaction conditions and tolerate an array of functional groups. Also demonstrated is the applicability of the strategy through several synthetic transformations of the products, as well as the syntheses of the natural product iso-moracin and the drug (E)-metanicotine.

Oxodealkenylative Cleavage of Alkene C(sp3 )-C(sp2 ) Bonds: A Practical Method for Introducing Carbonyls into Chiral Pool Materials.

Reported herein is a one-pot protocol for the oxodealkenylative introduction of carbonyl functionalities into terpenes and terpene-derived compounds. This transformation proceeds by Criegee ozonolysis of an alkene, reductive cleavage of the resulting α-alkoxy hydroperoxide, trapping of the generated alkyl radical with 2,2,6,6-tetramethylpiperidin-1-yl (TEMPO), and subsequent oxidative fragmentation with MMPP. Using readily available starting materials from chiral pool, a variety of carbonyl-containing products have been accessed rapidly in good yields.

Catalytic Asymmetric Staudinger-aza-Wittig Reaction for the Synthesis of Heterocyclic Amines.

Many natural products and medicinal drugs are heterocyclic amines possessing a chiral quaternary carbon atom in their heterocyclic ring. Herein, we report the first catalytic and asymmetric Staudinger-aza-Wittig reaction for the desymmetrization of ketones. This highly enantioselective transformation proceeds at room temperature to provide high yields-even on multigram scales-of nitrogen heterocycles featuring a chiral quaternary center. The products of this reaction are potential precursors for the synthesis of pharmaceuticals. A commercially available small P-chiral phosphine catalyst, HypPhos, induces the asymmetry and is recycled through in situ reduction of its oxide, mediated by phenylsilane in the presence of a carboxylic acid. The efficiency, selectivity, scalability, mild reaction conditions, and broad substrate scope portend that this process will expedite the syntheses of chiral heterocyclic amines of significance to chemistry, biology, and medicine.

Comparison of MRI cross-sectional area and functions of core muscles among asymptomatic individuals with and without lumbar intervertebral disc degeneration.

BACKGROUND: Previous studies suggested that patients with symptomatic intervertebral disc degeneration (IDD) of lumbar spine have reduced cross-sectional area (CSA) and functions of core muscles. However, reduced CSA and functions of core muscles have been observed not only in patients with symptomatic IDD but also in patients with other subgroups of low back pain (LBP). Thus, it is uncertain whether reduced CSA and functions of core muscles lead to IDD and LBP, or pain leads to reduced CSA and functions of core muscles in patients with symptomatic IDD. Therefore, this study aimed to compare the CSA and functions of core muscles between asymptomatic participants with and without IDD in magnetic resonance imaging (MRI). METHODS: Twenty asymptomatic participants (12 men and 8 women) participated in this study. Ten participants had asymptomatic IDD at L4-5. The others were healthy controls (without IDD at all levels of lumbar spine). The CSA of core muscles was measured using MRI. Maximal isometric trunk flexor strength and side bridge strength were measured by a Smart KEMA strength sensor. Trunk flexor endurance test, side bridge endurance test and plank endurance test were used to measure core endurance. Double legs loading test was used to measure core stability. Mann-Whitney U test was used to compare the differences between two groups. RESULTS: There were no significant differences in core muscle functions between the two groups (p > 0.05). Moreover, there was no significant difference in CSA between the two groups (p > 0.05). CONCLUSIONS: There was no significant difference in CSA and core muscle functions between asymptomatic participants with and without IDD. These findings indicate that a degenerative or bulging disc in asymptomatic individuals has little effect on CSA and functions of core muscles, especially in young age. Therefore, the general core endurance test or strength test could not differentiate asymptomatic people with and without IDD of lumbar spine. TRIAL REGISTRATION NUMBER: Clinical Research information Service. KCT0004061. Registered 13 June 2019. retrospectively registered.