Lower Extremity Muscle Research Articles

Miodynamic and Radiographic Evaluation in Recreative Athletes with Patellofemoral Pain

Background and Objectives: Patellofemoral pain (PFP) is frequent in the young and active population. The effect of muscle strength in the lower extremities after aerobic activity in patients with this condition has yet to be detailed. Our objective was to determine if patients with PFP show alterations in lower extremity muscle strength measurements after performing a session of ten minutes of aerobic activity on a treadmill compared to people without patellofemoral pain. Materials and Methods: We conducted a prospective experimental study with a stratified, non-randomized, and non-blinded population sample with group matching, including an experimental group with PFP and a control group with no pain. Subjects completed self-reported functional questionnaires (IKDC, Kujala, KOOS, SF-12), underwent radiographic studies, and were evaluated by measuring the strength of hip and knee muscles and the Single-Leg Triple-Hop (SLTH) test before and after ten minutes of exercise on a treadmill. Results: Seventeen subjects diagnosed with PFP and seventeen control subjects were evaluated. Both groups were homogeneous and had no significant differences in the demographic variables. A wider sulcus angle at 30° (136.8 ± 3.8° vs. 132.5 ± 5.6°, p = 0.0140), a decrease strength post-exercise in the hip abductor (37.9 ± 7.1 N⋅m vs. 45.6 ± 7.7 N⋅m, p < 0.05) and knee extensor (36.0 ± 9.1 N⋅m vs. 47.7 ± 14.0 N⋅m, p < 0.05), and a shorter distance in the SLTH test (337.9 ± 74.9 cm vs. 438.6 ± 65.8 cm, p < 0.01) was recorded in subjects with patellofemoral pain. Conclusions: Subjects with PFP had an overall lower strength of hip and knee muscles, showing significant differences in the hip abductors and knee extensors between people with PFP and healthy matched controls after aerobic exercise.

Case report: orthostatic hypotension as the first presentation of progressive encephalomyelitis with rigidity and myoclonus (PERM) with multiple autoimmune antibodies

IntroductionStiff person syndrome (SPS) is a rare disease characterized by axial and lower-extremity muscle rigidity, muscle spasm, and pain. Progressive encephalomyelitis with rigidity and myoclonus (PERM) is a variant of SPS. This case is particularly notable for its uncommon initial symptom: orthostatic hypotension, coupled with the presence of multiple antibodies. Such a presentation is a rarity in the context of PERM, thus providing a fresh and unique angle for both diagnosis and treatment.Case presentationThis case presents a 71-year-old man who was ultimately diagnosed with progressive encephalomyelitis with rigidity and myoclonus (PERM). His initial symptom was orthostatic hypotension, and we detected multiple antibodies such as GlyR antibody, GAD antibody, GM1-IgG and GQ1b-IgG in his serum. The patient showed partial response to glucocorticoid and immunoglobulin therapies, but as the disease recurred and progressed, plasma exchange, rituximab, and cyclophosphamide immunosuppressive therapy was administered, the prognosis remained poor. During follow-up after treatment, the patient developed pulmonary embolism and cardiac arrest, and died.ConclusionPERM exhibits diverse manifestation and pathogenic mechanisms. Immune heterogeneity affects clinical symptoms and prognosis. Cases of PERM combined with orthostatic hypotension and various antibodies have rarely been reported, the incidence and the specific mechanism is unknown, underscoring the need for further research. This case report underscores the importance of recognizing the diverse clinical presentations of PERM and the challenges in its diagnosis and management. It highlights autonomic dysfunction may be as the initial symptom of PERM. Moreover, it emphasizes the limitations of current treatment modalities and the necessity for further research to elucidate the underlying mechanisms and optimize therapeutic approaches for this debilitating autoimmune condition.

Effect of foot strike patterns and angles on the biomechanics of side-step cutting

ObjectivesThe study aimed to determine how foot strike patterns and cutting angles affect lower extremity (LE) kinematics, kinetics, and muscle activity during side-step cutting.MethodsTwenty male college sport athletes participated in this research. Three-dimensional motion analysis featuring ground reaction force (GRF) and electromyography (EMG) of the dominant leg was used. LE kinematics, kinetics, and EMG data parameters were obtained during a 45° and 90° side-step cutting involving rearfoot strikes (RFS) and forefoot strikes (FFS).ResultsThe significant foot strike pattern × angle interactions were observed for the ankle eversion range of motion (ROM) at the loading phase. Cutting of 90° had greater knee flexion ROM, knee valgus ROM, and knee varus moment compared to that of 45°. RFS cutting had greater knee flexion, hip flexion, knee valgus, knee varus moment, knee varus moment, and ankle eversion ROM. FFS cutting produced a lower vertical GRF, lateral GRF, and a loading rate. Both vastus medialis and vastus lateralis muscle activities were remarkably greater during cutting of 90° than 45°. At the loading phase, semitendinosus, biceps femoris, and the lateral head of gastrocnemius muscle activities during FFS cutting were considerably greater than those during RFS cutting.ConclusionThe FFS pattern can better protect the anterior cruciate ligament (ACL) and improve the flexibility of athletes by increasing the plantarflexion torque of the ankle. The injury risk also increases with the larger cutting angle. The EMG activities of semitendinosus and biceps femoris are vital for the stability of knee joint during side-step cutting, which helps reduce ACL stress during buffering.

Muscle structure assessment using synchrotron radiation X-ray micro-computed tomography in murine with cerebral ischemia.

Muscles are crucial for balance and walking, activities which depend specifically on the lower extremity muscles. Therefore, the evaluation of stroke induced atrophy and paralysis is essential; however, determining the extent of damage in the days after its occurrence remains challenging. In this study, we evaluated ischemic stroke-induced soleus muscle damage in gerbils using synchrotron radiation X-ray micro-computed tomography (SR-µCT), comparing a control group (n = 3), animals 7 days after stroke (7 d, n = 3), and animals 14 days after stroke (14 d, n = 3). The left muscle was paralyzed, whereas the right muscle was not. Subsequently, we quantified the assessment by segmenting the soleus muscle based on the extracellular space/matrix and fiber region to determine the degree of damage. The muscle fiber-to-extracellular space/matrix ratio were significantly damaged due to paralysis on the left side (control vs. 14 d, P = 0.040). Muscle area was significantly different at 14 d between the left and right sides (P = 0.010). Additionally, the left local fascicle surface area, thickness, global pennation angle, and local fascicle angle were significantly different between the control and 14 d groups (P = 0.002, P = 0.007, P = 0.005, and P = 0.014 respectively). These findings underscore the potential of post-stroke animal studies in improving rehabilitation treatment for the central nervous system by assessing the degree of muscle recovery.

Dynamic Analysis of Upper- and Lower-Extremity Performance During Take-Offs and Landings in High-Wall Climbing: Effects of a Plyometric and Strength Training Intervention

This study used a 12-week plyometric and strength training program as an intervention to improve upper- and lower-extremity muscle strength for jumping and landing when climbing high walls. Sixty general non-athlete male college students were openly recruited and divided into an experimental group and a control group. The experimental group underwent a plyometric and strength training program twice a week for 12 weeks (24 sessions). The intervention was divided into three phases, each lasting four weeks, with the training intensity gradually increasing in each phase. A hand grip dynamometer was used to measure grip strength, and a PASCO double-track force plate was used to assess upper-extremity push-up force and lower-extremity take-off and landing strength. The results of the 12-week intervention showed that the experimental group experienced significant increases in grip strength (both hands), hand-ground reaction force, and upper-extremity hang time. Additionally, the time of upper-extremity action on the force plate decreased. Lower-extremity take-off strength improved, as reflected in increased ground reaction force, rate of force development, and passage time. Upon landing, ground reaction force decreased by 3.2%, and cushioning time shortened by 52.7%. This study concludes that plyometric and strength training have promising effects in enhancing upper- and lower-extremity strength, particularly in climbing and landing tasks.

Assessing Intensive Care Unit Acquired Weakness: An Observational Study Using Quantitative Ultrasound Shear Wave Elastography of the Rectus Femoris and Vastus Intermedius

IntroductionIntensive care unit-acquired weakness (ICUAW) is associated with unfavorable outcomes. The current diagnostic tools for ICUAW are invasive, yield delayed results, and lack precision. This study explored the potential of shear wave elastography (SWE), an innovative ultrasound technique, to evaluate the quality changes in the lower extremity muscles of ICU patients, potentially aiding the early detection of ICUAW. Materials and MethodsWe included adult patients diagnosed with ICUAW (average Medical Research Council score < 48) from December 2020 to October 2021. ICU patients were continuously monitored twice daily. Using ultrasonography, we measured the thickness (TH), cross-sectional area (CSA), pennation angle (PA), and SWE (SWE-values) modulus of the bilateral rectus femoris (RF) and vastus intermedius (VI). The diagnostic performance of each parameter was evaluated using sensitivity, specificity, and area under the receiver operating characteristic curve. ResultsUltrasound quantification assessments were performed in 47 patients, 24 with ICUAW and 23 without ICUAW. Notably, PA decreased (RF: 11.33%, VI: 10.51%), while muscle rigidity increased (RF: 22.39%, VI: 22.50%) in ICUAW patients compared with non-ICUAW patients. The sensitivity and specificity for PA in the RF were 79.17% and 91.30%, respectively, and those for PA in VI were 79.17% and 78.26%, respectively. The use of both combinations yielded 91.67% and 73.91% sensitivity and specificity, respectively. Employing the PA of RF and SWE-values of RF together, we observed a diagnostic prediction sensitivity of 91.67% and a specificity of 60.87%. ConclusionsICUAW patients exhibited increased rigidity of the lower extremity muscles during their hospital stay. Ultrasonic SWE emerged as a reliable and objective tool, offering significant diagnostic value for ICUAW.

Changes in lower extremity muscle coordination over a 30-minute walk do not differ by muscle fatigability

Changes in lower extremity muscle coordination over a 30-minute walk do not differ by muscle fatigability

Comparison of synergy extrapolation and static optimization for estimating multiple unmeasured muscle activations during walking

BackgroundCalibrated electromyography (EMG)-driven musculoskeletal models can provide insight into internal quantities (e.g., muscle forces) that are difficult or impossible to measure experimentally. However, the need for EMG data from all involved muscles presents a significant barrier to the widespread application of EMG-driven modeling methods. Synergy extrapolation (SynX) is a computational method that can estimate a single missing EMG signal with reasonable accuracy during the EMG-driven model calibration process, yet its performance in estimating a larger number of missing EMG signals remains unknown.MethodsThis study assessed the accuracy with which SynX can use eight measured EMG signals to estimate muscle activations and forces associated with eight missing EMG signals in the same leg during walking while simultaneously performing EMG-driven model calibration. Experimental gait data collected from two individuals post-stroke, including 16 channels of EMG data per leg, were used to calibrate an EMG-driven musculoskeletal model, providing “gold standard” muscle activations and forces for evaluation purposes. SynX was then used to predict the muscle activations and forces associated with the eight missing EMG signals while simultaneously calibrating EMG-driven model parameter values. Due to its widespread use, static optimization (SO) applied to a scaled generic musculoskeletal model was also utilized to estimate the same muscle activations and forces. Estimation accuracy for SynX and SO was evaluated using root mean square errors (RMSE) to quantify amplitude errors and correlation coefficient r values to quantify shape similarity, each calculated with respect to “gold standard” muscle activations and forces.ResultsOn average, compared to SO, SynX with simultaneous model calibration produced significantly more accurate amplitude and shape estimates for unmeasured muscle activations (RMSE 0.08 vs. 0.15, r value 0.55 vs. 0.12) and forces (RMSE 101.3 N vs. 174.4 N, r value 0.53 vs. 0.07). SynX yielded calibrated Hill-type muscle–tendon model parameter values for all muscles and activation dynamics model parameter values for measured muscles that were similar to “gold standard” calibrated model parameter values.ConclusionsThese findings suggest that SynX could make it possible to calibrate EMG-driven musculoskeletal models for all important lower-extremity muscles with as few as eight carefully chosen EMG signals and eventually contribute to the design of personalized rehabilitation and surgical interventions for mobility impairments.

Effectiveness of NDT method in cases of Cerebral Palsy Ataxia

Background: As many as 2.5% of children out of 1000 live births in the world have a higher risk of developing CP, and as many as 70% of CP occurs if the baby's birth weight is low, infections during pregnancy and the child's growth and development, obstruction of the birth canal, and stress experienced by the mother. causes the baby to experience CP. Objective: The case study aims to determine the benefits of the NDT approach method for CP Ataxia in improving movement control, eliciting reflexes, increasing core stability and lower extremity muscle strength, and increasing functional activity. Method: In the case of CP Ataxia, the NDT method is used in the form of handling with falling reflex training, handling with training standing on a balance board, facilitation with training getting up and down a balance board, facilitation with walking and pushing a chair. Evaluation was carried out 4 times over 3 weeks with GMFM, and checking balance reflexes. Results: After physiotherapy, it was found that there was an increase in movement control, the emergence of reflexes in children where the appearance of the protective side ward reflex increased starting at T3, while the emergence of the paracute side ward reflex began at T4. There was an increase in muscle strength and functional activity measured by GMFM, resulting in T1 63.36%; T2 63.36%; T3 64.36%; T4 67.3%. Conclusion: The NDT approach as a method for managing CP Ataxia with 4x therapy for 3 weeks is effective in improving movement control, eliciting reflexes, increasing core stability and lower extremity muscle strength, and increasing functional activity.

Effects of Supervised Exercise Therapy on Muscle Function During Walking in Patients with Peripheral Artery Disease

Background: Although supervised exercise therapy (SET) is a primary treatment for peripheral artery disease (PAD), the current literature is limited regarding the mechanisms contributing to increased walking distances, including how lower extremity muscle function is altered after SET. This study aimed to investigate the effects of SET on lower extremity muscle function during walking in patients with PAD. Methods: Twelve patients with PAD participated in a 6-month SET program consisting of three weekly exercise sessions (a total of 72 sessions) and adhered to the American College of Sports Medicine’s (ACSM) recommendations. Each session started with a 5 min warm-up of mild walking and static stretching of upper and lower body muscles, followed by 50 min of intermitted exercise on a treadmill, and then finished with 5 min of cool-down activities similar to the warm-up. Each patient walked across a 10 m pathway with reflective markers on their lower limbs twice: before (baseline) and after six months of participation in SET (post-exercise). Marker coordinates and ground reaction forces were recorded and imported to OpenSim software (version 4.0) for gait simulations. Muscle force, muscle power, and metabolic rate were estimated from OpenSim and compared between the baseline and post-exercise. Results: The mean plantar flexor force was not altered after SET. However, individuals’ plantar flexor muscles demonstrated improvements in force production (lateral gastrocnemius: 75–80% of stance, Cohen’s d = 0.20–0.43; medial gastrocnemius: 65–85% of stance, Cohen’s d = 0.20–0.71; soleus: 90–95% of stance, Cohen’s d = 0.20–0.26). Furthermore, plantar flexor power increased (80–95% of stance, Cohen’s d = 0.20–0.39) and this was attributed to increased power in the lateral gastrocnemius (80–85% of stance, Cohen’s d = 0.20–0.47), medial gastrocnemius (80–90% of stance, Cohen’s d = 0.22–0.60), and soleus muscles (85–95% of stance, Cohen’s d = 0.20–0.49). Similarly, other muscle groups (knee extensors, knee flexors, hip abductors, hip adductors, hip extensors, and hip flexors) also exhibited force and power increases after SET. Additionally, force and power variances were significantly decreased in several muscle groups (plantar flexors, knee extensors, hip abductors, hip external rotators, hip extensors, and hip flexors). Total metabolic rate also increased during the stance period where muscle force and power were elevated after SET (early stance: 5–25%, Cohen’s d = 0.20–0.82; mid stance: 35–45%, Cohen’s d = 0.20–0.47; late stance: 75–80%, Cohen’s d = 0.20–0.36). Conclusions: Our results suggest that from a biomechanics perspective, muscle functions during walking are improved in patients with PAD after SET; however, the improvements were generally small and were not reflected by all muscle groups.

Advanced quantitative magnetic resonance imaging of lower extremity muscle microtrauma after marathon: a mini review.

This article reviews the existing literature and outlines recent advances in quantitative Magnetic Resonance Imaging (MRI) techniques for the assessment of lower extremity muscle microtrauma following a marathon. Single-modality quantitative MRI techniques include T2 mapping to assess the dynamics of muscle inflammatory edema and variability at the site of injury, Diffusion Tensor Imaging (DTI) to detect subclinical changes in muscle injury, Intravoxel Incoherent Motion (IVIM) imaging to provide simultaneous information on perfusion and diffusion in muscle tissue without the need for intravenous contrast, and Magnetic Resonance Spectroscopy (MRS) to noninvasively detect intramyocellular lipid (IMCL)content in muscle before and after marathon exercise to explain the use of fatty acids as an energy source in skeletal muscle during long-distance running. As well as Chemical Exchange Saturation Transfer (CEST) is particularly suitable for detecting changes in free creatine, pH values and lactate concentrations in muscles before and after exercise, providing a more detailed picture of muscle physiology and chemistry. These metabolic MRI methods enhance the understanding of biochemical alterations occurring in muscles pre- and post-exercise. Multimodal techniques combine different modalities to provide a comprehensive evaluation of muscle structural and functional changes. These advanced techniques aim to better assess microtrauma and guide clinical treatment, though further validation with larger studies is needed to establish their potential over traditional qualitative methods.

A rare cause of low back pain: lumbar lateral meningocele

Lumbar meningocele is the herniation of the arachnoid mater enlarged neural foramen to the thecal sac. A 55-year-old female patient applied with low back pain. Physical examination there were multiple cutaneous neurofibromas. The strength of lower extremity muscles was normal bilaterally. Babinski sign was negative bilaterally with normoactive deep tendon reflexes. Lumbal magnetic resonance imaging images show ectasia. The diagnosis was lateral meningocele associated with neurofibromatosis. Lumbar meningocele is a benign pathology that can be seen in a wide range from asymptomatic to paraparesis, which does not require surgical treatment, unless it is symptomatic, which is frequently associated with NF1. Key words: Lateral meningocele, Neurofibromatosis Type 1, Low back pain

Effects of Toe-Strengthening Exercises on Medial Longitudinal Arch Height, Muscle Stiffness, and Functional Movement

Background: Prolonged training in combat boots can place significant stress on the medial longitudinal arch, potentially leading to lower-extremity muscle stiffness and an increased risk of injury. This study assessed the impact of toe-strengthening exercises on improving the lower-extremity function and functional movement in cadets undergoing training. Methods: Forty junior cadets (mean age: 22.6 years) participated in this study. The measurements included the medial longitudinal arch height, lower-extremity muscle stiffness, functional movement, and leg length. Results: Cadets who performed the toe exercises demonstrated improved lower-extremity muscle stiffness and functional movement performance (hurdle step, p = 0.010; rotary stability, p = 0.001). A significant correlation was observed between the exercise group and time (tibialis right, p = 0.008; tibialis left, p = 0.028). Conclusions: This study highlighted the potential of toe-strengthening exercises to enhance the lower-extremity function and reduce the risk of injury among cadets. However, challenges in identifying the medical history, past injuries, and specific areas of pain for each cadet were noted. These findings support the implementation of targeted toe exercises in military training programs to prevent injuries.

Lower limbs kinematic analysis during a jump landing task in soccer players with unilateral anterior cruciate ligament reconstruction

BackgroundFatigue leads to an acute decline in muscle strength, altered patterns of lower extremity muscle activation, changes in hip and knee kinematics. In terms of the effects of fatigue on knee joint kinematics during plyometric training, there is still a lack of knowledge regarding kinematic differences between athletes who passed the ACL reconstructions rehabilitation period and healthy athletes. Therefore, this study aimed to compare lower limb joint kinematic parameters between reconstructed cruciate ligament and healthy control soccer players during jump landing in a fatigued setting.MethodsLower limb kinematic parameters were recorded in 20 professional soccer players (age, 24.95 ± 2.92 years; body mass, 77.20 ± 12.88 kg; height, 1.77 ± 3.19 m) during jump landing task before and after the fatigue protocol. The control group consisted of healthy subjects and the experimental group consisted of subjects with ACL reconstruction by thigh transplantation. Kinematic data was recorded with 4 cameras to measure lower limb angles at first foot contact and maximum range of motion.ResultsThe results showed that before fatigue, there was only a significant difference between the two groups in the maximum range of motion of the non-involved hip joint (P = 0.022) and angle of the involved hip at first contact (P = 0.049). In other data on joint range of motion or initial contact angle, no significant difference was observed between the two groups (P > 0.05). After fatigue protocol, there was a significant difference in initial foot contact in non-involved (P = 0.030), and involved (P = 0.020) hip joint angles between the two groups. However, no significant difference in initial contact angle or range of motion of other joints was observed between the groups.ConclusionsThis study shows that plyometric fatigue does not contribute to numerous changes in contact angles and range of motion in lower extremity joints in healthy soccer players and those with a history of cruciate ligament repairs.

An expository analysis of biomechanical and subjective impacts induced by shoe inserts in asymptomatic subjects: A systematic review on functionality and mechanisms of action

AbstractThis systematic review explores the biomechanical and subjective effects of shoe inserts, including foot orthotics (FOs) and insoles, in asymptomatic subjects. Aimed at understanding their implications, the review poses two key research questions: (i) the influence of shoe inserts on lower extremity biomechanics and subjective perception and (ii) the effects of different design characteristics on these aspects. Following Preferred Reporting of Systematic Reviews and Meta‐Analysis guidelines, a meticulous search of Scopus and PubMed from August 2022 to March 2023 yielded 34 articles, with 26 focusing on biomechanical effects and eight on comfort effects. The studies, conducted during static and dynamic activities, such as standing, walking, jogging, running, jumping, and cycling, reveal significant reductions in rearfoot eversion, knee joint forces, and lower extremity muscle forces through postings and wedging in FOs. Changes in stiffness impact rearfoot kinematics, plantar pressure distribution, and ankle–foot power distribution. Conversely, surface texture and arch variations demonstrate limited significance. FOs and shoe inserts, characterized by geometric, material, location, size, and fabrication features, effectively regulate forces and moments on the lower extremity. This control promotes uniform plantar pressure distribution and enhances comfort during various activities. These insights benefit manufacturers, clinicians, and stakeholders, providing a deeper understanding of the positive benefits of FOs and shoe inserts. However, further well‐designed studies on clinical populations are necessary to validate these findings and establish their clinical efficacy, as the current focus remains on healthy subjects.

Intersession Intra-Rater and Inter-Rater Reliability of Myotonometer for Upper and Lower Extremity Muscles in Children with Spinal Muscular Atrophy.

Background/Objectives: This study aimed to examine intra- and inter-rater reliability of a myotonometer (MyotonPRO) in measuring upper and lower extremity mechanical properties in children with spinal muscular atrophy types I and II. Methods: Biceps brachii, triceps brachii, rectus femoris, and gastrocnemius muscle tone and stiffness in children (n = 21) were measured using the MyotonPRO device. Examiner 1 performed two sets of measurements in 60 min to determine intra-rater reliability. Examiner 2 performed measurements between Examiner 1's sets. Intra-interclass correlation coefficient, minimal detectable change, and standard error of measurement values were calculated to assess intra- and inter-rater reliabilities in this cross-sectional study. Results: The results showed excellent intra- and inter-rater reliability analyses for frequency and stiffness values except for the stiffness value of the gastrocnemius muscle, which presented good reliability (ICC = 0.71). Minimal detectable change values ranged from 0.59 to 1.98 Hz for muscle tone and 16.08 to 124.74 N/m for stiffness (for both intra- and inter-rater reliabilities). Conclusions: Our findings indicate that MyotonPRO is a reliable tool for quantifying upper and lower extremity mechanical properties within one session in children with spinal muscular atrophy types I and II. Mechanical properties of the extremity muscle can be determined using this easily applied tool in future studies.

Modified tai chi movement training based on sEMG and movement analysis on improving upper extremities motor function: a protocol for a clinical randomised controlled trial

IntroductionStroke survivors often face motor dysfunction, increasing fall risk. Lower extremity muscle weakness is a key factor affecting walking ability. Tai chi (TC) has been shown to improve muscle strength...

Feasibility of telehealth exercise and nicotinamide riboside supplementation in survivors of childhood cancer at risk for diabetes: A pilot randomized controlled trial.

Childhood cancer survivors (CCS) have a 50% higher risk of diabetes mellitus (DM) compared with the general population. Interventions in survivors with prediabetes (fasting glucose 100-125mg/dL or hemoglobin A1c 5.7%-6.4%) may mitigate the development of DM and its attendant morbidity, but there is limited information on the feasibility of secondary prevention in this setting. This 6-week pilot feasibility 1:1 randomized controlled trial enrolled 20 CCS on a structured telehealth exercise program±nicotinamide riboside (NR), a nicotinamide adenine dinucleotide precursor. Feasibility metrics were: (1)≥50% of eligible CCS enrolled onto study; (2)≥70% of participants completed baseline and end-of-study assessments; (3)≥70% compliance with exercise and NR. Secondary endpoints included changes in biomarkers associated with glucose homeostasis and muscle health. Median age (years) at cancer diagnosis was 16.5 (range, 1.5-21.5) and 35.5 (range, 18.0-67.0) at study enrollment. Enrollment rate was 87%, and 85% of participants completed baseline and end-of-study assessments. The mean percentage of exercise sessions completed was 86.6%; NR compliance was>90%. There were no severe adverse events attributable to study interventions. Secondary endpoints were not significantly different between study arms at study completion. Myostatin decrease was observed in participants who completed a higher median number of exercise sessions and was associated with decreased intramuscular adipose tissue and increased lower extremity muscle cross-sectional area. A telehealth exercise intervention±NR supplementation was feasible in CCS with prediabetes. Future studies in larger cohorts may be needed to evaluate their beneficial effects on muscle health and DM risk among CCS.

6541 Recurrent Euglycemic Diabetic Ketoacidosis And Myonecrosis In A Patient Previously Thought To Have Type 2 Diabetes Mellitus

Abstract Disclosure: K. Haridas: None. M.M. McConnell : None. Introduction: Euglycemic diabetic ketoacidosis (DKA) is a well-recognized complication with the use of sodium linked cotransport of glucose-2 (SGLT2) inhibitors. Diabetic myonecrosis is a rare complication of diabetes mellitus caused by spontaneous death of muscle due to microvascular ischemia. Clinical Case: A 48-year-old male diagnosed with Type 2 Diabetes Mellitus with HbA1c 11.3%, treated with Empagliflozin and basal-bolus insulin was admitted to the hospital with left thigh pain and anorexia. Physical examination was notable for BMI of 19kg/m2 and left lateral thigh induration. Laboratory evaluation revealed venous pH 7.1, bicarbonate 10mmol/L (20-30), anion gap 32mmol/L(8-12), glucose 168mg/dl (65-99), ESR 67mm/h (&amp;lt;=12), Creatinine Kinase 31 U/L (63-473), glucosuria (4+) and ketonuria (4+). He was diagnosed with euglycemic DKA due to SGLT2 inhibitor. He was also diagnosed with Type 1 Diabetes Mellitus (T1DM) based on undetectable C-peptide and GAD antibody titer 64.3IU/ml(&amp;lt;5). MRI of the left thigh revealed an area of diabetic myonecrosis, measuring 11cm. He was treated with continuous insulin infusion. On hospital day 3, after resolution of the anion gap metabolic acidosis, transition was made to basal-bolus insulin. On hospital day 5, recurrent euglycemic DKA was diagnosed with bicarbonate 15mmol/L, anion gap 18mmol/L, beta-hydroxybutyrate 49.6mg/dl (&amp;lt;=3mg/dl), glucose 185mg/dl, glucosuria (4+) and ketonuria (4+). Continuous insulin infusion was restarted. On hospital day 8, transition was made to subcutaneous insulin. Diabetic myonecrosis was initially managed conservatively with analgesics, aspirin, and physical therapy. Due to worsening leukocytosis on hospital day 13, Ceftriaxone was started and surgical debridement was performed, revealing a loculated abscess within necrotic muscle. Empagliflozin was discontinued at discharge. Discussion: The risk of euglycemic DKA with SGLT2i use is increased in patients with T1DM and decreased oral intake, and insults like trauma or surgery as seen in this patient. Although the half-life of empagliflozin is 12 to 14 hours, there have been case reports of persistent or recurrent euglycemic DKA for 7-12 days from the time of last dose. The continued glucosuria and ketonuria in this patient with serum glucose levels below the renal threshold confirmed the recurrence. Diabetic myonecrosis usually affects the muscles of the proximal lower extremities and is seen in patients with poorly controlled diabetes with microvascular complications, between one and two decades after diagnosis, as in this patient. Conclusion: A high index of suspicion for recurrent euglycemic DKA must be maintained in patients who have new or persistent high anion gap metabolic acidosis until 2 weeks from last dose of SGLT2 inhibitor. Diabetic myonecrosis, especially if complicated by abscess formation, may require surgical intervention. Presentation: 6/1/2024

The effect of squats on muscle activity in standing, kneeling, and half-kneeling positions: A cross-sectional study.

Kneeling and half-kneeling training are common positions used in physical therapy. however, research on lower extremity muscle activity is lacking compared to the ergonomic aspects and trunk muscle activity. The purpose of this study is to investigate the effects on lower extremity muscle activity during squats in kneeling and half-kneeling positions. The study was designed as a cross-sectional study with a single group of healthy adults. Participants were instructed to perform squats while assuming 3 positions (standing, kneeling, and half-kneeling). Surface electromyography data were recorded 3 times from the rectus femoris (RF), gluteus maximus (GMax), gluteus medius (GMed), and biceps femoris (BF) on the participant's dominant side, and the mean values were analyzed. The participants performed squats for 9 seconds, with 4 seconds of the descent phase, 1 second of the maintenance phase, and 4 seconds of the ascent phase. A metronome was used to ensure precise timing. The study included 30 participants (19 males and 11 females). The muscle activities of the RF, GMed, and BF showed statistically significant differences among the 3 positions, being highest in the half-kneeling position (HKP), followed by the standing position (SP) and kneeling position (KP). The muscle activity of the GMax was significantly higher in the HKP than in the SP and KP (P < .05). The co-contraction ratio was significantly higher with KP than with the SP and HKP (P < .05). In the SP and KP, there were statistically significant differences between the ascent and descent phases of the RF, GMax, GMed, and BF (P < .05). In the HKP, there were statistically significant differences between the ascent and descent phases of the RF, GMax, and GMed (P < .05). The results of this study indicate that squats in the HKP (especially during the ascent phase) require the highest muscle activity, whereas squats in the KP (especially during the descent phase) can be performed with the lowest muscle activity. It can be concluded that these findings could serve as selective indicators for squat exercises and in enhancing postural control, muscle strength, and lower extremity stabilization.