Adaptive Lifting Index (aLI) for Real-Time Instrumental Biomechanical Risk Assessment: Concepts, Mathematics, and First Experimental Results.

When performing lifting tasks at work, the Lifting Index (LI) is widely used to prevent work-related low-back disorders, but it presents criticalities pertaining to measurement accuracy and precision. Wearable sensor networks, such as sensorized insoles and inertial measurement units, could improve biomechanical risk assessment by enabling the computation of an adaptive LI (aLI) that changes over time in relation to the actual method of carrying out lifting. This study aims to illustrate the concepts and mathematics underlying aLI computation and compare aLI calculations in real-time using wearable sensors and force platforms with the LI estimated with the standard method used by ergonomists and occupational health and safety technicians. To reach this aim, 10 participants performed six lifting tasks under two risk conditions. The results show us that the aLI value rapidly converges towards the reference value in all tasks, suggesting a promising use of adaptive algorithms and instrumental tools for biomechanical risk assessment.

Estimating Compressive and Shear Forces at L5-S1: Exploring the Effects of Load Weight, Asymmetry, and Height Using Optical and Inertial Motion Capture Systems.

This study assesses the agreement of compressive and shear force estimates at the L5-S1 joint using inertial motion capture (IMC) within a musculoskeletal simulation model during manual lifting tasks, compared against a top-down optical motion capture (OMC)-based model. Thirty-six participants completed lifting and lowering tasks while wearing a modified Plug-in Gait marker set for the OMC and a full-body IMC set-up consisting of 17 sensors. The study focused on tasks with variable load weights, lifting heights, and trunk rotation angles. It was found that the IMC system consistently underestimated the compressive forces by an average of 34% (975.16 N) and the shear forces by 30% (291.77 N) compared with the OMC system. A critical observation was the discrepancy in joint angle measurements, particularly in trunk flexion, where the IMC-based model underestimated the angles by 10.92-11.19 degrees on average, with the extremes reaching up to 28 degrees. This underestimation was more pronounced in tasks involving greater flexion, notably impacting the force estimates. Additionally, this study highlights significant differences in the distance from the spine to the box during these tasks. On average, the IMC system showed an 8 cm shorter distance on the X axis and a 12-13 cm shorter distance on the Z axis during lifting and lowering, respectively, indicating a consistent underestimation of the segment length compared with the OMC system. These discrepancies in the joint angles and distances suggest potential limitations of the IMC system's sensor placement and model scaling. The load weight emerged as the most significant factor affecting force estimates, particularly at lower lifting heights, which involved more pronounced flexion movements. This study concludes that while the IMC system offers utility in ergonomic assessments, sensor placement and anthropometric modeling accuracy enhancements are imperative for more reliable force and kinematic estimations in occupational settings.

Regression-Based Machine Learning for Predicting Lifting Movement Pattern Change in People with Low Back Pain.

Machine learning (ML) algorithms are crucial within the realm of healthcare applications. However, a comprehensive assessment of the effectiveness of regression algorithms in predicting alterations in lifting movement patterns has not been conducted. This research represents a pilot investigation using regression-based machine learning techniques to forecast alterations in trunk, hip, and knee movements subsequent to a 12-week strength training for people who have low back pain (LBP). The system uses a feature extraction algorithm to calculate the range of motion in the sagittal plane for the knee, trunk, and hip and 12 different regression machine learning algorithms. The results show that Ensemble Tree with LSBoost demonstrated the utmost accuracy in prognosticating trunk movement. Meanwhile, the Ensemble Tree approach, specifically LSBoost, exhibited the highest predictive precision for hip movement. The Gaussian regression with the kernel chosen as exponential returned the highest prediction accuracy for knee movement. These regression models hold the potential to significantly enhance the precision of visualisation of the treatment output for individuals afflicted with LBP.

Effect of low back pain on the kinetics and kinematics of the lumbar spine - a combined in vivo and in silico investigation.

Lifting is a significant risk factor for low back pain (LBP). Different biomechanical factors including spinal loads, kinematics, and muscle electromyography (EMG) activities have previously been investigated during lifting activities in LBP patients and asymptomatic individuals to identify their association with LBP. However, the findings were contradictory and inconclusive. Accurate and subject-specific prediction of spinal loads is crucial for understanding, diagnosing, planning tailored treatments, and preventing recurrent pain in LBP patients. Therefore, the present study aimed to estimate the L5-S1 compressive and resultant shear loads in 19 healthy and 17 non-specific chronic LBP individuals during various static load-holding tasks (holding a 10 kg box at hip, chest, and head height) using full-body and personalized musculoskeletal models driven by subject-specific in vivo kinematic/kinetic, EMG, and physiological cross-sectional areas (PCSAs) data. These biomechanical characteristics were concurrently analyzed to identify potential differences between the two groups. Statistical analyses showed that LBP had almost no significant effect on the range of motion (trunk, lumbar, pelvis), PCSA, and EMG. There were no significant differences (p > 0.05) in the predicted L5-S1 loads. However, as the task became more demanding, by elevating the hand-load from hip to head, LBP patients experienced significant increases in both compressive (33 %, p = 0.00) and shear (25 %, p = 0.02) loads, while asymptomatic individuals showed significant increases only in compressive loads (30 %, p = 0.01). This suggests that engaging in more challenging activities could potentially magnify the effect of LBP on the biomechanical factors and increase their discrimination capacity between LBP and asymptomatic individuals.

Conventional video recordings dependably quantify whole-body lifting strategy using the Stoop-Squat-Index: A methods comparison against motion capture and a reliability study.

Whole-body lifting strategies could be derived from conventional video recordings using the Stoop-Squat-Index, which quantifies the ratio between trunk forward lean and lower extremity joint flexion from 0 (full squat) to 100 (full stoop). The purpose of this study was to compare Stoop-Squat-Indices derived from conventional video recordings to those from a three-dimensional marker-based motion capture system and to evaluate interrater and intrarater reliability of the video-based approach. Thirty healthy participants lifted a 5-kg box under different conditions (freestyle, squat, stoop). Kinematic data were recorded using a Vicon motion capture system (serving as reference standard) and an iPad camera. Stoop-Squat-Indices over the entire lifting cycle were derived separately from both approaches. Agreement was assessed using mean differences (video minus motion capture) and limits of agreement. Reliability was investigated by calculating intraclass correlation coefficients (ICC) and minimal detectable changes (MDC) over the course of the lifting cycle. Systematic errors were identified with Statistical Parametric Mapping-based T-tests. Systematic errors between the video-based and the motion capture-based approach were observed among all conditions. Mean differences in Stoop-Squat-Indices over the lifting cycle ranged from -6.9 to 3.2 (freestyle), from -1.8 to 5.3 (squat) and from -2.8 to -1.1 (stoop). Limits of agreement were lower when the box was close to the floor, and higher towards upright standing. Reliability of the video-based approach was excellent for most of the lifting cycle, with ICC above 0.995 and MDC below 3.5. These findings support using a video-based assessment of Stoop-Squat-Indices to quantify whole-body lifting strategy in field.

Electromyography-driven musculoskeletal models with time-varying fatigue dynamics improve lumbosacral joint moments during lifting.

Muscle fatigue is prevalent across different aspects of daily life. Tracking muscle fatigue is useful to understand muscle overuse and possible risk of injury leading to musculoskeletal disorders. Current fatigue models are not suitable for real-world settings as they are either validated using simulations or non-functional tasks. Moreover, models that capture the changes to muscle activity due to fatigue either assume a linear relationship between muscle activity and muscle force or utilize a simple muscle model. Personalised electromygraphy (EMG)-driven musculoskeletal models (pEMS) offer person-specific approaches to model muscle and joint kinetics during a wide repertoire of daily life tasks. These models utilize EMG, thus capturing central fatigue-dependent changes in multi-muscle bio-electrical activity. However, the peripheral muscle force decay is missing in these models. Thus, we studied the influence of fatigue on a large scale pEMS of the trunk. Eleven healthy participants performed functional asymmetric lifting task. Average peak body-weight normalized lumbosacral moments (BW-LM) were estimated to be 2.55 ± 0.26 Nm/kg by reference inverse dynamics. After complete exhaustion of the lower back, the pEMS overestimated the peak BW-LM by 0.64 ± 0.37 Nm/kg. Then, we developed a time-varying muscle force decay model resulting in a time-varying pEMS (t-pEMS). This reduced the difference between BW-LM estimated by the t-pEMS and reference to 0.49 ± 0.14 Nm/kg. We also showed that five fatiguing contractions are sufficient to calibrate the t-pEMS. Thus, this study presents a person and muscle specific model to track fatigue during functional tasks.

Determining whether biomechanical variables that describe common 'safe lifting' cues are associated with low back loads.

Lift technique training programs have been implemented to help reduce injury risk, but the underlying content validity of cues used within these programs is not clear. The objective of this study was to determine whether biomechanical variables, that commonly used lifting cues aim to elicit, are associated with resultant low back extensor moment exposures. A sample of 72 participants were recruited to perform 10 repetitions of a floor-to-waist height barbell lift while whole-body kinematics and ground reaction forces were collected. Kinematic, kinetic, and energetic variables representative of characteristics commonly targeted by lifting cues were calculated as predictor variables, while peak and cumulative low back moments were calculated as dependent measures. Multiple regression revealed that 56.6-59.2% of variance in low back moments was explained by predictor variables. From these regression models, generating motion with the legs (both greater hip and knee work), minimizing the horizontal distance of the body to the load, maintaining a stable body position, and minimizing lift time were associated with lower magnitudes of low back moments. These data support that using cues targeting these identified variables may be more effective at reducing peak low back moment exposures via lift training.

The effect of gradually lifting the two-child policy on demographic changes in China.

Low-fertility rate has been a common problem in many industrialized countries. To reverse the declining trend of new births, Chinese government gradually lifted its restrictions on the number of births per family, allowing for a household to have no more than two children. Little is known about the additional births or population increase contributed by the gradual relaxation of birth restrictions. To fill this gap, this quasi-experimental design study including data from 124 regions used the synthetic control method and controlled interrupted time series analysis to evaluate the differences in birth rates and rates of natural population increase between China and its synthetic control following implementation of the two-child policy from 2011 to 2020. A total of 123 regions were included in the control pool. Data collected during 1990-2010 were used to identify the synthetic China for each study outcome. The mean rate differences of birth rates and rates of natural increase between China and synthetic China after two-child policy implementation were 1.16 per 1000 population and 1.02 per 1000, respectively. These rate differences were distinguished from variation due to chance (one-sided pseudo-P-values: P for birth rates = 0.047, P for rates of natural increase = 0.020). However, there were statistically significant annual reductions in the pre-post trend of birth rates and rates of natural increase compared with those of controls of <0.340 per 1000 population per year [P = 0.007, 95% CI = (-0.584, -0.096)] and <0.274 per 1000 per year [P = 0.028, 95% CI = (-0.518, -0.031)]. The results suggested that lifting birth restrictions had a short-term effect on the increase in birth rates and rates of natural population increase. However, birth policy with lifting birth restrictions alone may not have sustained impact on population growth in the long run.

In vivo load on knee, hip and spine during manual materials handling with two lifting techniques.

It is generally accepted that the lifting technique strongly influences physical loads within the human body and, thus, the risk of musculoskeletal disorders. However, there is a lack of knowledge regarding whether particular lifting techniques are effective in reducing loads. Hence, this retrospective study quantified (partly published) in vivo loads at joints within the human body during two typical lifting techniques, stoop lifting and squat lifting. Patients who had received instrumented implants underwent in vivo load measurements at either the knee (two patients), the hip (eight patients), or the upper lumbar spine (four patients) while lifting a 10 kg weight frontally with either straight (stoop) or bent (squat) knees. Contact forces and moments and the orientation of the contact force vector were determined and examined using the paired t test of Statistical Parametric Mapping. The two lifting techniques did not differ in terms of load magnitudes but did differ in terms of directions: (i) at the hip joint, the load vector varied significantly (p < 0.05) in the frontal and sagittal planes, (ii) at the knee joint, the load vector differed significantly (p < 0.05) in the sagittal plane (iii) while the load vector and magnitude did not differ at the upper lumbar spine (p > 0.05). Our findings indicate that the lifting technique causes changes in the orientation rather than the magnitude of lower extremity joint contact loads. Even though this quantification could only be performed in a small group of patients, the quantification of the relevance of such lifting technique recommendations will hopefully guide future recommendations towards a more scientific interpretation.

Exploring how metronome pacing at varying movement speeds influences local dynamic stability and coordination variability of lumbar spine motion during repetitive lifting.

Auditory metronomes have been used to preserve movement consistency when examining local dynamic stability (LDS) and coordination variability (CV) of lumbar spine motion during repetitive movements. However, the potential influence of the metronome itself on these outcome measures has rarely been considered. Therefore, this study investigated the influence of different metronome paces (i.e., lifting speeds) on measures of lumbar spine LDS and thorax-pelvis CV during a repetitive lifting/lowering task in comparison to self-paced movements. Ten participants completed 5 repetitive lift/lower trials, where participants completed 35 consecutive repetitions (analysis on last 30 repetitions) at a self-selected pace for the first and last trial, and were paced by a 10 lift/min, 15 lift/min, and 20 lift/min metronome, in randomized order, for the remaining three trials. The average self-paced lift/lower speed before and after experiencing the three different metronome paced speeds was 16.2 (±1.02) and 17.2 (±0.73) lifts/min, respectively, and the most-preferred metronome pace trial was 15 lifts/min. Thorax-pelvis CV during the self-paced trials were similar (p > 0.05) to the 15 lift/min metronome paced trials, while greater thorax-pelvis CV was observed for the 10 lift/min compared to the 15 lift/min and 20 lift/min and second self-paced trial (all p < 0.026). This movement speed effect was not observed for lumbar spine LDS; however, more-dynamically stable movements were observed during all metronome paced trials in comparison to the self-paced trials. This study highlights that careful consideration is required when employing a metronome to control/manipulate movement characteristics while examining neuromuscular control using non-linear dynamical systems measures.

Recent Advancements in Pectus Surgery: Crane Lifting, Multiple-Bar Approach, Bridge Stabilization, and Sandwich Technique.

PURPOSE: The most recent procedure for pectus excavatum repair involves crane-powered entire chest wall remodeling, which employs crane lifting, multiple-bar approach, bridge stabilization, and sandwich techniques. This resulted in a paradigm shift in pectus deformity repair from merely lifting the sunken bone to remodeling the chest wall into normal anatomy. METHODS: We analyzed 649 patients who underwent surgery for pectus excavatum or complex combined deformities between March 2018 and January 2022. A crane with sternal wiring or screwing was used to lift the chest wall without using the pectus bar turning power. Multiple bars with bridge connections were placed to eliminate bar displacement. Modified sandwich techniques were applied to relieve the lower coastal flare (flare-buster) and focal protuberance (magic string). RESULTS: The mean age of the patients included in the study was 12.2 years (range: 3-45 years). A single bar was used for 202 patients until 2021. For the multiple-bar technique, parallel bars (n = 142), crossbars (n = 166), and crossbars plus upper horizontal bars (XI pattern; n = 139) were used. The overall complication rate was 6.2 %. There was no cases of bar displacement were observed, but other minor complications such as pneumothorax (n = 20, 3.1 %), pleural effusion (n = 7, 1.1 %), and wound infection (n = 5, 0.8 %) were detected. Three patients required reoperation (infection, two: hemorrhage, one). CONCLUSIONS: The crane-powered entire chest wall remodeling technique improved the safety and comprehensiveness of the repair procedure. By incorporating bridge stabilization and the use of multiple bars, we effectively resolved the issues related to bar displacement and incomplete repair. TYPE OF STUDY: Retrospective Cohort Study.

Long-Term Improvement of Crow's Feet Wrinkles in Combination With Cervicofacial and Temporal Lifting: Review of the Literature.

BACKGROUND: The lateral orbital crow's feet area is one for which rejuvenation is most frequently requested by patients. Moreover, lateral canthal wrinkles are a common source of dissatisfaction after rhytidoplasty. Botulinum toxin injection has emerged as a most popular, easy, and effective solution; nevertheless, repeated injections are required periodically for long-term effect. Other nonsurgical options have also been described to have some demonstrable advantages. Orbicularis oculi surgical manipulations have been described as well. MATERIAL AND METHODS: A systematic PubMed literature search was conducted to identify clinical cohort studies including more than 10 patients describing surgical approaches for improvement of crows' feet wrinkles in combination with face and/or temporal lifts. The search was complemented by Embase, Medline, and Cochrane searches in addition to screening of reference lists of selected studies and simple term searches about surgical treatment of crow's feet. RESULTS: Fourteen studies satisfied the inclusion criteria and were included in this review describing various muscle excision techniques including vertical strip excision, lateral partial resection, wedge resection, muscle resection in "C" pattern, and enlarged myectomy of about one-third of the whole orbital extension in addition to muscle manipulation modalities, including muscle splaying, muscle division, muscle division and splaying, muscle undermining with partial denervation, and muscle suspension. Interposition of fascia between orbicularis muscle and overlying skin was also reported. CONCLUSION: View the few studies retrieved and the wide spectrum of reported techniques, it is not possible to determine from this review the most effective modality. Nevertheless, it seems that subcutaneous undermining of the lateral canthal area combined with splaying and traction of the orbicularis oculi muscle and fixation to the temporalis fascia with or without muscle division would yield the best long-term results. This review indicates also that surgical correction of crow's feet during rhytidectomy or temporal lift could be a positive complement to improve aesthetic outcome. Unfortunately, if not underreported, it is definitely neglected. We believe that this review may be an eye-opener for surgeons.

The Effect of an Overhead External Load Lifting and Lowering on Dynamic Postural Control in Subgroups of Low Back Pain.

BACKGROUND: Understanding postural control in low back pain (LBP) subgroups can help develop targeted interventions to improve postural control. The studies on this topic are limited. Therefore, the primary purpose of this study was to compare the postural control of LBP subgroups with healthy individuals during overhead load lifting and lowering. METHODS: In this cross-sectional study, the participants were 52 with LBP and 20 healthy. The LBP patients were classified based on the O'Sullivan classification system into 21 flexion patterns and 31 active extension patterns. The participants lifted the box from their waists to their overheads and lowered it to their waists. Changes in postural control parameters were measured with a force plate system. RESULTS: The results of the analysis of variance showed that during load lifting, the mediolateral phase plane (p = .044) and the mean total velocity (p = .029) had significant differences between flexion patterns and healthy. Also, the load-lowering results showed that active extension patterns, compared with healthy, had significant differences in the anteroposterior-mediolateral phase plane (p = .042). The patients showed less postural sway than the healthy. CONCLUSIONS: The results in this work highlight the importance of identifying the homogenous subgroups in LBP and support the classification of heterogeneous LBP. Different subgroups exhibit different postural control behaviors. These behaviors can be due to the loading of various tissues during different tasks.

Sternal lifting technique for patients with sternal depression during robotic mitral repair.

INTRODUCTION: Traditional surgical methods have been difficult for patients with chest wall deformities, but the use of the Electrical Sternum Lifting System (ESLS) has made the surgery easier. MATERIALS AND SURGICAL TECHNIQUE: Patients with a sternum-to-vertebral distance of less than 80 mm on preoperative computed tomography (CT) scan routinely underwent sternal lift using the ESLS. The ESLS was effective in securing the operative field while suspending the sternum, allowing adequate observation of the left atrium, left ventricle, and the mitral valve, and safe mitral valve plasty. The use of the lifting device did not interfere with the robot arms, and the space between the sternum and vertebrae was widened with only a 3 mm wound to move the mitral valve surface in the sagittal plane, making the repair easy and accurate under robotic assistance. The effort to attach the ESLS was not difficult, and the postoperative cosmetic outcomes were excellent. Sixty-three out of 1002 patients (6.3%) underwent sternal elevation using ESLS. There were 19 males and 44 females with a mean age of 50.9 ± 14.0 years. The average of sternum-to-vertebral (S/V) distance was 72.4 ± 8.9 cm. Two patients had S/V distance of more than 80 mm but ESLS was used because of scoliosis.

Association of objectively measured lifting load with low-back pain, stress, and fatigue: A prospective cohort study.

OBJECTIVES: Limited knowledge exists about the association of lifting loads on a daily basis with physical and mental symptoms among warehouse workers. This study investigated associations between objectively measured lifting load and low-back pain (LBP), mental stress, and bodily fatigue after work and the following morning. METHODS: Warehouse workers (N=85) from the retail industry replied to daily questionnaires before and after work for 21 days about LBP intensity, mental stress, and bodily fatigue (outcome, all scales 0-10). We assessed lifting exposure using company records from the warehouse logistic systems on total lifting load (kg) per workday. Associations between variables were tested using linear mixed models with repeated measures controlling for relevant confounders. RESULTS: Mean daily lifting load was 1667.2 kg (range: 0-9998.4 kg). Compared to lifting 0-499 kg during a workday, lifting 500-1999 kg was associated with 0.59 points [95% confidence interval (CI) 0.10-1.08] elevated LBP intensity after work, while lifting ≥5000 showed a higher LBP intensity of 1.26 points (95% CI 0.48-2.03). LBP intensity remained elevated the following morning. Lifting ≥5000 kg was associated with higher mental stress after work of 0.74 points (95% CI 0.10-1.37), while no association was observed for bodily fatigue. CONCLUSIONS: Higher daily lifting loads were associated with higher LBP intensity after work and the following morning. These findings suggest that warehouses should consider the daily lifting loads when organizing warehouse work to prevent development of LBP, eg, using company records to provide a more equal distribution of daily lifting loads between workers.

An artificial neural network for full-body posture prediction in dynamic lifting activities and effects of its prediction errors on model-estimated spinal loads.

Musculoskeletal models have indispensable applications in occupational risk assessment/management and clinical treatment/rehabilitation programs. To estimate muscle forces and joint loads, these models require body posture during the activity under consideration. Posture is usually measured via video-camera motion tracking approaches that are time-consuming, costly, and/or limited to laboratories. Alternatively, posture-prediction tools based on artificial intelligence can be trained using measured postures of several subjects performing many activities. We aimed to use our previous posture-prediction artificial neural network (ANN), developed based on many measured static postures, to predict posture during dynamic lifting activities. Moreover, effects of the ANN posture-prediction errors on dynamic spinal loads were investigated using subject-specific musculoskeletal models. Seven individuals each performed twenty-five lifting tasks while their full-body three-dimensional posture was measured by a 10-camera Vicon system and also predicted by the ANN as functions of the hand-load positions during the lifting activities. The measured and predicted postures (i.e., coordinates of 39 skin markers) and their model-estimated L5-S1 loads were compared. The overall root-mean-squared-error (RMSE) and normalized (by the range of measured values) RMSE (nRMSE) between the predicted and measured postures for all markers/tasks/subjects was equal to 7.4 cm and 4.1 %, respectively (R2 = 0.98 and p < 0.05). The model-estimated L5-S1 loads based on the predicted and measured postures were generally in close agreements as also confirmed by the Bland-Altman analyses; the nRMSE for all subjects/tasks was < 10 % (R2 > 0.7 and p > 0.05). In conclusion, the easy-to-use ANN can accurately predict posture in dynamic lifting activities and its predicted posture can drive musculoskeletal models.

An Enhanced Spine Model Validated for Simulating Dynamic Lifting Tasks in OpenSim.

A fully articulated thoracolumbar spine model had been previously developed in OpenSim and had been extensively validated against experimental data during various static tasks. In the present study, we enhanced this detailed musculoskeletal model by adding the role of passive structures and adding kinematic constraints to make it suitable for dynamic tasks. We validated the spinal forces estimated by this enhanced model during nine dynamic lifting/lowering tasks. Moreover, we recently developed and evaluated five approaches in OpenSim to model the external loads applied to the hands during lifting/lowering tasks, and in the present study, we assessed which approach results in more accurate spinal forces. Regardless of the external load modeling approach, the maximum forces predicted by our enhanced spine model across all tasks, as well as the pattern of estimated spinal forces within each task, showed strong correlations (r-values and cross-correlation coefficients > 0.9) with experimental data. Given the biofidelity of our enhanced model, its accessibility via the open-source OpenSim software, and the extent to which this model has been validated, we recommend it for applications requiring estimation of spinal forces during lifting/lowering tasks using multibody-based models and inverse dynamic analyses.

Evaluating the impact of lifting mandatory smoking cessation prior to elective abdominal wall reconstruction. A single-center experience.

INTRODUCTION: Many studies identify active smoking as a significant risk factor for postoperative wound and mesh complications in patients undergoing abdominal wall reconstruction surgery. However, our group conducted an analysis using data from the ACHQC database, which revealed similar rates of surgical site infection (SSI) and surgical site occurrence requiring procedural intervention (SSOPI) between active smokers and non-smokers As a result, the Cl eveland Clinic Center for Abdominal Core Health instituted a policy change where active smokers were no longer subject to surgical delay. Our study aims to evaluate the impact of active smoking on the outcomes of these patients. METHODS: We identified active smoking patients who had undergone open, elective, clean ventral hernia repair (VHR) with transversus abdominis release (TAR) and permanent synthetic mesh at Cleveland Clinic Foundation. Propensity matching was performed to create a 1:3 ratio of "current-smokers" and "never-smokers" and compared wound complications and all 30-day morbidity between the two groups. RESULTS: 106 current-smokers and 304 never-smokers were matched. Demographics were similar between the two groups after matching, with the exception of chronic obstructive pulmonary disease (COPD) (22.1% vs. 13.4%, p â€‹< â€‹.001) and body mass index (BMI) (31.1 vs. 32.6, p â€‹= â€‹.02). Rates of SSI (12.2% vs. 6.9%, p â€‹= â€‹.13), SSO (21.7% vs. 13.2%, p â€‹= â€‹.052), SSOPI (11.3% vs. 6.3%, p â€‹= â€‹.13), and reoperation (1.9% vs. 3.9%, p â€‹= â€‹.53) were not significantly different between active smokers and never-smokers correspondingly. One case (0.3%) of partial mesh excision was observed in the never-smokers group (p â€‹= â€‹1). The current-smokers group exhibited a significantly higher incidence of pneumonia compared to the never-smokers group (5.7% vs. 0.7%, p â€‹= â€‹.005). CONCLUSION: Our study revealed that operating on active smokers did result in a slight increase in wound morbidity, although it did not reach statistical significance. Additionally, pulmonary complications were higher in the smoking group. Notably, we did not see any mesh infections in the smoking group during early follow up. We believe that this data is important for shared decision making on patients that are actively smoking contemplating elective hernia repair.

Differential effects of sex on upper body kinematics and kinetics during fatiguing, Asymmetric lifting.

This study quantified sex-specific biomechanical adaptations to fatigue in asymmetric lifting. Twenty-one females and fifteen males performed a prolonged asymmetric lifting protocol while upper body, trunk and pelvis kinematics were collected. Features of movement identified with principal component analysis, and peak joint angular velocities and moments were calculated. Sex-specific kinematic adaptations to fatigue included females adopting a 'stoop-like' lifting strategy to a greater extent than males. Additionally, females exhibited higher vertical elbow positions during load rotation, moved their body toward the destination for load deposit, and did not reduce peak right shoulder flexion velocities, in contrast to male participants. Females also had greater low back and shoulder peak normalized joint moments. When fatigued, females adopted an asymmetric lifting strategy that minimized metabolic demand as supported by smaller decreases in maximum voluntary contractions. However, females' fatigue-related adaptations increased biomechanical exposures associated with injury risk.

Relationship between cumulative exposure to occupational lifting throughout working life and risk of ischemic heart disease in men and women. The Copenhagen Aging and Midlife Biobank.

Ischemic heart disease (IHD) causes mortality and morbidity. High levels of occupational physical activity (OPA) increases IHD risk, and occupational lifting (OL) is suggested as a detrimental OPA exposure. This study investigated the association between accumulated OL throughout working life, and risk for IHD, and potential sex and hypertension differences. Data from Copenhagen Ageing and Midlife Biobank linked to register-based information on incident IHD during 9 years follow-up in the Danish National Patient Registry were included. The outcome was the odds of IHD from baseline (2009-2011) to end of follow-up (2018), among participants without IHD at baseline. Accumulated OL was assessed by linking occupational codes to a Job Exposure Matrix, creating a measure in ton-years (lifting 1,000 kg/day/year). Multivariable logistic regression tested associations between level of accumulated OL and IHD, among the 6,606 included individuals (68% men). During follow-up, 7.3% men and 3.6% women were hospitalized with IHD. Among all participants, the odds for IHD were 47% (OR 1.47, 95% CI 1.05-2.06) higher among those with ≥5 to <10 ton-years, 39% (OR 1.39, 95% CI 1.06-1.83) higher among those with ≥10 to <30 ton-years, and 62% (OR 1.62, 95% CI 1.18-2.22) higher among those with ≥30 ton-years, compared to no accumulated OL. However, these increased odds were in the same direction in the fully-adjusted model but statistically insignificant, ≥5 to <10 ton-years OR 1.28, 95% CI 0.88-1.88; ≥10 to <30 ton-years OR 1.20, 95% CI 0.85-1.69; and ≥30 ton-years OR 1.22, 95% CI 0.81-1.84. No statistically significant interactions, nor any associations, between OL and sex, or hypertension were seen.