Biomechanical Assessment Research Articles

Biomechanical Assessment of a Novel Sharp-Tipped Screw for 1-Step Minimally Invasive Pedicle Screw Placement Under Navigation.

The objective of this study was to assess the pullout force of a novel sharp-tipped screw developed for single-step, minimally invasive pedicle screw placement guided by neuronavigation compared with the pullout force for traditional screws. A total of 60 human cadaveric lumbar pedicles were studied. Three different screw insertion techniques were compared: (A) Jamshidi needle and Kirschner wire without tapping; (B) Jamshidi needle and Kirschner wire with tapping; and (C) sharp-tipped screw insertion. Pullout tests were performed at a displacement rate of 10 mm/min recorded at 20 Hz. Mean values of these parameters were compared using paired t tests (left vs right in the same specimen): A vs B, A vs C, and B vs C. Additionally, 3 L1-L5 spine models were used for timing each screw insertion technique for a total of 10 screw insertions for each technique. Insertion times were compared using 1-way analysis of variance. The mean pullout force for insertion technique A was 1462.3 (597.5) N; for technique B, it was 1693.5 (805.0) N; and for technique C, it was 1319.0 (735.7) N. There was no statistically significant difference in pullout force between techniques (P > 0.08). The average insertion time for condition C was significantly less than that for conditions A and B (P < 0.001). The pullout force of the novel sharp-tipped screw placement technique is equivalent to that of traditional techniques. The sharp-tipped screw placement technique appears biomechanically viable and has the advantage of saving time during insertion. Single-step screw placement using high resolution 3-dimensional navigation has the potential to streamline workflow and reduce operative time.

Biomechanical CT to Assess Bone After Sleeve Gastrectomy in Adolescents With Obesity: A Prospective Longitudinal Study.

Sleeve gastrectomy (SG) is effective in treating cardiometabolic complications of obesity but is associated with bone loss. Our aim was to determine the effect of SG on the lumbar spine by biomechanical CT analysis in adolescents/young adults with obesity. We hypothesized that SG would lead to a decrease in strength and bone mineral density (BMD) compared with nonsurgical controls. In a 12-month prospective nonrandomized study, adolescents/young adults with obesity underwent SG (n=29, 18.0 ± 2.1 years, 23 female) or were followed without surgery (controls, n=30, 17.95 ± 3.0 years, 22 female). At baseline and 12months, participants underwent quantitative computed tomography (QCT) of L1 and L2 for biomechanical assessment and MRI of the abdomen and mid-thigh for body composition assessment. Twelve-month changes between groups and within groups were assessed. Analyses were controlled for baseline and 12-month changes in body mass index (BMI) by multivariable analyses. Regression analysis was performed to evaluate the effect of body composition on bone parameters. Our institutional review board (IRB) approved the study, and informed consent/assent was obtained. Participants in the SG group had a higher baseline BMI than controls (p=0.01) and lost an average of 34.3 ± 13.6kg 12months after surgery, whereas weight was unchanged in controls (p < 0.001). There were significant reductions in abdominal adipose tissue and thigh muscle area in the SG group compared with controls (p < 0.001). Bone strength, bending stiffness, and average and trabecular volumetric BMD decreased in the SG group compared with controls (p < 0.001). After controlling for change in BMI, a 12-month reduction in cortical BMD was significant in the SG group compared with controls (p=0.02). Reductions in strength and trabecular BMD were associated with reductions in BMI, visceral adipose tissue, and muscle (p ≤ 0.03). In conclusion, SG in adolescents decreased strength and volumetric BMD of the lumbar spine compared with nonsurgical controls. These changes were associated with decreases in visceral fat and muscle mass. © 2023 American Society for Bone and Mineral Research (ASBMR).

Concurrent endurance training with either plyometric or dynamic body-weight training both improve running economy with minimal or no changes in running biomechanics

ABSTRACT We compared the effects of two 8-week concurrent strength and endurance trainings (CSETs) on running economy (RE) and running biomechanics, and we explored whether the effects on running biomechanics were mediated by responder status [high vs low responder based on −2.6% change in RE]. Thirty-one male recreational runners were randomly assigned to a standard endurance running training combined with either plyometric (CSET-PLY) or dynamic body-weight (CSET-DYN) training. RE and running biomechanics [contact (tc ) and flight (tf ) time, step frequency (SF), duty factor (DF), and leg stiffness (k leg)] were measured pre- and post-intervention. RE significantly improved following CSET (RE = −2.1 ± 3.9%; p = 0.005) and no changes in tc , DF, SF, and k leg (p ≥ 0.10) but a shorter tf (p ≥ 0.03) from pre- to post-intervention were seen. The prevalence of high responders was 42% (RE = −5.7 ± 2.4%). Among high responders, there were no changes in running biomechanics except participants following CSET-DYN who increased their SF (+3%). These results indicate that improvements in RE obtained through CSET-PLY and CSET-DYN involve minimal to no changes in running biomechanics and that there was not a training modality, which was better than the other. More detailed biomechanical assessments involving kinematics, kinetics, and electromyography could shed light on the underlying mechanisms of RE improvement.

Ex Vivo Biomechanical Assessment of Various Repair Techniques in a Rabbit Calcaneal Tendon Avulsion Model: Application of Polycaprolactone Plate

This study was aimed at evaluating the biomechanical properties and gapping characteristics of tendon repair methods using a combination of a three-loop pulley (3LP) pattern, a titanium plate, and a polycaprolactone (PCL) plate in a rabbit gastrocnemius tendon (GT) model (n = 50). GTs were randomly assigned to five groups (n = 10/group). Transected GTs were repaired with a 3LP pattern alone or in conjunction with an epitendinous suture (ES), a 5-hole 1 mm PCL plate, a 5-hole 2 mm PCL plate, or a 5-hole 1.5 mm titanium plate. The yield, peak, and failure force, as well as the occurrence and force of 1-mm and 3-mm gapping were examined. The mean yield, peak, and failure force of the 3LP + titanium plate group were higher than that of other groups. The biomechanical properties of a 3LP + a 2 mm PCL plate were similar to 3LP + ES constructs in this model. In all specimens in all groups, 1 mm gap formation was observed. The frequency of 3 mm gap formation was 70% and 90% in the 3LP + 2 mm PCL plate group and the 3LP + 1.5 mm titanium plate group, respectively. Additional studies evaluating PCL plates to determine the effect on the healing and blood supply of tendon are needed.

Biomechanical Assessments of the Upper Limb for Determining Fatigue, Strain and Effort from the Laboratory to the Industrial Working Place: A Systematic Review.

Recent human-centered developments in the industrial field (Industry 5.0) lead companies and stakeholders to ensure the wellbeing of their workers with assessments of upper limb performance in the workplace, with the aim of reducing work-related diseases and improving awareness of the physical status of workers, by assessing motor performance, fatigue, strain and effort. Such approaches are usually developed in laboratories and only at times they are translated to on-field applications; few studies summarized common practices for the assessments. Therefore, our aim is to review the current state-of-the-art approaches used for the assessment of fatigue, strain and effort in working scenarios and to analyze in detail the differences between studies that take place in the laboratory and in the workplace, in order to give insights on future trends and directions. A systematic review of the studies aimed at evaluating the motor performance, fatigue, strain and effort of the upper limb targeting working scenarios is presented. A total of 1375 articles were found in scientific databases and 288 were analyzed. About half of the scientific articles are focused on laboratory pilot studies investigating effort and fatigue in laboratories, while the other half are set in working places. Our results showed that assessing upper limb biomechanics is quite common in the field, but it is mostly performed with instrumental assessments in laboratory studies, while questionnaires and scales are preferred in working places. Future directions may be oriented towards multi-domain approaches able to exploit the potential of combined analyses, exploitation of instrumental approaches in workplace, targeting a wider range of people and implementing more structured trials to translate pilot studies to real practice.

Cervical vertebrae for early bone loss evaluation in osteoporosis mouse models.

Osteoporosis (OP), a systemic skeletal disease common in aged population, is an important public health problem worldwide. Animal models are important tools for understanding OP. In ovariectomy (OVX) or orchiectomy (ORX) OP models, lumbar vertebrae are often used for evaluating of the OP progression. However, unlike the bipeds, the lumbar vertebrae are not weight loading bones in quadruped animal, but the head-bearing cervical vertebrae take much higher stress. So, we compared the murine cervical vertebrae with lumbar vertebrae for OP assessment. OVX and ORX mouse models were established on C57BL/6J mice. Serum estradiol, testosterone and bone related biomarkers were verified. Bone quantity and quality were determined using micro computed tomography (micro-CT) analysis. Hard tissue sections were prepared, stained for histomorphological analyzing, and micro-indentation measured for bone mechanical property evaluation. In OVX and ORX mice, serum estradiol or testosterone levels reduced, bone resorption level and related biomarkers elevated, indicated the successful generation of the OP models. In the early stage, the trabecular bone mineral density (BMD) of cervical vertebrae was already reduced 16.1% (OVX) and 21.7% (ORX) one-month post-gonadectomy, respectively; while this decline in the fifth lumbar vertebra were only 5% and 7.4%, respectively. Six months post-gonadectomy, the reduction of BMD in cervical vertebrae and the fifth lumbar vertebra were 31.2% & 36.1% and 28.5% & 30.7% respectively. In biomechanical aspects, cervical spines showed worse Vickers hardness (HV) and elastic modulus than lumbar spine in six-month OVX and ORX mice. We provide a new OP early-stage evaluation mouse model based on the cervical spine. Through the radiographic, biological and biomechanical assessments, the mouse cervical spine is more suitable for bone remodeling evaluation in OP models than the conventional lumbar vertebrae, especially for early-stage OP study.

Simultaneous Assessment of the Whole Eye Biomechanics Using Ultrasonic Elastography.

Current elastography techniques in the field of ophthalmology usually target one specific tissue, such as the cornea or the sclera. However, the eye is an inter-related organ, and some ocular diseases can alter the biomechanical properties of multiple anatomical structures. Hence, there is a need to develop an imaging tool that can non-invasively, quantitatively, and accurately characterize dynamic changes among these biomechanical properties. A high resolution ultrasound elastography system was developed to achieve this goal. The efficacy and accuracy of the system was first validated on tissue-mimicking phantoms while mechanical testing measurements served as the gold standard. Next, an in vivo elevated intraocular pressure (IOP) model was established in rabbits to further test our system. In particular, elastography measurements were obtained at 5 IOP levels, ranging from 10 mmHg to 30 mmHg in 5 mmHg increments. Spatial-temporal maps of the multiple ocular tissues (cornea, lens, iris, optic nerve head, and peripapillary sclera) were obtained. The spatial-temporal maps were acquired simultaneously for the ocular tissues at the 5 different IOP levels. The statistical analysis of the elastic wave speed was presented for ocular tissues. Finally, the mapping for the elastic wave speed of each ocular component was acquired at each IOP level. Our elastography system can concurrently assess the biomechanical properties of multiple ocular structures and detect changes in biomechanical properties associated with changes in IOP. This system provides a novel tool to measure and quantify the biomechanical properties of the whole eye.

Comparison of Ectasia Detection in Early Keratoconus Using Scheimpflug-Based Corneal Tomography and Biomechanical Assessments.

The aim of this study was to determine the detection of keratoconus using corneal biomechanical parameters only, a corneal tomographic parameter only, and a parameter that combines corneal biomechanical and tomographic indices. The discriminatory power of the Pentacam Random Forest Index (PRFI), Belin/Ambrósio Enhanced Ectasia Display (BAD-D) index, Corvis Biomechanical Index (CBI), and Tomographic and Biomechanical Index (TBI) to differentiate between normal eyes (n = 84), eyes with very asymmetric corneal ectasia (VAE-E, n = 21), and the fellow eyes without apparent ectasia based on normal tomography (VAE-NT, n = 21) was assessed. Statistical analyses were completed with R software using t-tests, Wilcoxon rank sum tests, and receiver operating characteristic (ROC) curves. The DeLong test was used to compare the area under the ROC curve (AUROC). The TBI and PRFI had the highest AUROC when distinguishing between normal and VAE-E corneas (AUROC = 1.00, 95% CI = 1.00-1.00); however, they were not statistically superior to the CBI (AUROC = 0.97, P = 0.27) or BAD-D (AUROC = 1.00, P = 0.34). The TBI (AUROC = 0.92, 95% CI = 0.86-0.98) was superior to CBI (AUROC = 0.78, P = 0.02) and BAD-D (AUROC = 0.81, P = 0.02) when distinguishing between healthy and VAE-NT corneas. At a threshold of 0.72, the TBI had 99% sensitivity, 67% specificity, and 92% accuracy in distinguishing normal and VAE-NT corneas. The TBI is a useful parameter for the screening of subclinical and frank keratoconus in tomographically normal eyes.

Supersonic shear wave elastography of human tendons is associated with in vivo tendon stiffness over small strains

Supersonic shear wave (SW) elastography has emerged as a useful imaging modality offering researchers and clinicians a fast, non-invasive, quantitative assessment of tendon biomechanics. However, the exact relationship between SW speed and in vivo tendon stiffness is not intuitively obvious and needs to be verified. This study aimed to explore the validity of supersonic SW elastography against a gold standard method to measure the Achilles tendon’s in vivo tensile stiffness by combining conventional ultrasound imaging with dynamometry. Twelve healthy participants performed maximal voluntary isometric plantarflexion contractions (MVC) on a dynamometer with simultaneous ultrasonographic recording of the medial gastrocnemius musculotendinous junction for dynamometry-based measurement of stiffness. The tendon’s force–elongation relationship and stress–strain behaviour were assessed. Tendon stiffness at different levels of tension was calculated as the slope of the stress–strain graph. SW speed was measured at the midportion of the free tendon and tendon Young’s modulus was estimated. A correlation analysis between the two techniques revealed a statistically significant correlation for small strains (r(10) = 0.604, p =.038). SW-based assessments of in vivo tendon stiffness were not correlated to the gold standard method for strains in the tendon>10 % of the maximum strain during MVC. The absolute values of SW-based Young’s modulus estimations were approximately-three orders of magnitude lower than dynamometry-based measurements. Supersonic SW elastography should be only used to assess SW speed for the detection and study of differences between tissue regions, differences between people or groups of people or changes over time in tendon initial stiffness (i.e., stiffness for small strains).

A Comparison of Inertial Measurement Units and Overnight Videography to Assess Sleep Biomechanics.

The assessment of sleep biomechanics (comprising movement and position during sleep) is of interest in a wide variety of clinical and research settings. However, there is no standard method by which sleep biomechanics are measured. This study aimed to (1) compare the intra- and inter-rater reliability of the current clinical standard, manually coded overnight videography, and (2) compare sleep position recorded using overnight videography to sleep position recorded using the XSENS DOT wearable sensor platform. Ten healthy adult volunteers slept for one night with XSENS DOT units in situ (on their chest, pelvis, and left and right thighs), with three infrared video cameras recording concurrently. Ten clips per participant were edited from the video. Sleeping position in each clip was coded by six experienced allied health professionals using the novel Body Orientation During Sleep (BODS) Framework, comprising 12 sections in a 360-degree circle. Intra-rater reliability was assessed by calculating the differences between the BODS ratings from repeated clips and the percentage who were rated with a maximum of one section of the XSENS DOT value; the same methodology was used to establish the level of agreement between the XSENS DOT and allied health professional ratings of overnight videography. Bennett's S-Score was used to assess inter-rater reliability. High intra-rater reliability (90% of ratings with maximum difference of one section) and moderate inter-rater reliability (Bennett's S-Score 0.466 to 0.632) were demonstrated in the BODS ratings. The raters demonstrated high levels of agreement overall with the XSENS DOT platform, with 90% of ratings from allied health raters being within the range of at least 1 section of the BODS (as compared to the corresponding XSENS DOT produced rating). The current clinical standard for assessing sleep biomechanics, manually rated overnight videography (as rated using the BODS Framework) demonstrated acceptable intra- and inter-rater reliability. Further, the XSENS DOT platform demonstrated satisfactory levels of agreement as compared to the current clinical standard, providing confidence for its use in future studies of sleep biomechanics.

Disturbances of the ascending aorta biomechanics in moderate dilatation and aneurysm

Aim. To compare disturbances of the ascending aorta (AA) biomechanics in pa­­tients with moderate dilatation and aneurysm using segmental aortic strain ultrasound.Material and methods. Fifteen patients with moderate AA dilatation (40-49 mm), 17 patients with AA aneurysm (≥50 mm) and 11 healthy volunteers (AA&lt;40 mm) were examined using 2D multiplane transesophageal echocardiography (TEE). The entire thoracic aorta (TA) was assessed. Using 2D speckle-tracking TEE, global peak systolic circumferential strain (GCS, %), global peak systolic circumferential strain normalized to pulse pressure (GCS/PP) and aortic stiffness (β2) index at 4 TA levels (sinuses of Valsalva, sinotubular junction, mid-ascending aorta, descending aorta) were calculated.Results. In healthy volunteers with TA diameter of 26,6 mm (25,2; 28,4) unidi­rec­tional uniform GCS of 9,7% (8,4; 11,7), GCS/PP of 18,4 (14,9; 2,.6) and uniform aortic stiffness (β2) 5,9 (4,8; 6,7) in all TA segments were revealed. There was a pro­portionally significant decrease in deformation parameters up to negative values and an increase of the ascending aortic wall stiffness from the aortic annulus to the descending aorta with a maximum in the highest dilatation zone in patients with moderate dilatation and aneurysm. Moreover, in these patients aortic wall strain and stiffness did not differ in all TA segments (p&gt;0,05). The AA diameter in maximum dilatation zone in patients with aneurysm was significantly higher than in patients with moderate dilatation — 52 mm (51; 55) versus 47 mm (45; 48), p&lt;0,001, respectively. An inverse correlation between the AA diameter in maximum dilatation zone and aortic strain (GCS: r=-0,61; p&lt;0.001 and GCS/PP: r=-0,62; p&lt;0,001) and a direct correlation with the aortic stiffness (β2) index (r=0,56; p&lt;0,05) were revealed.Conclusion. Assessment of the aortic biomechanics along with the AA diameter has an independent diagnostic value when choosing an individual surgical strategy in patients with moderate dilatation and AA aneurysm.

Changes in biomechanics, strength, physical function, and daily steps after extended-release corticosteroid injections in knee osteoarthritis: a responder analysis.

To determine changes in gait biomechanics, quadricep strength, physical function, and daily steps after an extended-release corticosteroid knee injection at 4 and 8weeks post-injection in individuals with knee osteoarthritis as well as between responders and non-responders based on changes in self-reported knee function. The single-arm, clinical trial included three study visits (baseline, 4weeks, and 8weeks post-injection), where participants received an extended-release corticosteroid injection following the baseline visit. Time-normalized vertical ground reaction force (vGRF), knee flexion angle (KFA), knee abduction moment (KAM), and knee extension moment (KEM) waveforms throughout stance were collected during gait biomechanical assessments. Participants also completed quadricep strength, physical function (chair-stand, stair-climb, 20-m fast-paced walk) testing, and free-living daily step assessment for 7days following each visit. All participants demonstrated increased KFA excursion (i.e., greater knee extension angle at heel strike and KFA at toe-off), increased KEM during early stance, improved physical function (all p < 0.001), and increased quadricep strength at 4 and 8weeks. KAM increased throughout most of stance at 4 and 8weeks post-injection (p < 0.001) but appears to be driven by gait changes in non-responders. Non-responders demonstrated lesser vGRF during late stance and lesser KEM and KFA throughout stance compared to responders at baseline. Extended-release corticosteroid injections demonstrated short-term improvements in gait biomechanics, quadricep strength, and physical function for up to 4weeks. However, non-responders demonstrated gait biomechanics associated with osteoarthritis progression prior to the corticosteroid injection, suggesting that non-responders demonstrate more deleterious gait biomechanics prior to corticosteroid injection. Key Points • Individuals with knee osteoarthritis who were treated with extended-release corticosteroid injections demonstrated improvements in gait biomechanics and physical function for 8weeks. • Individuals with knee osteoarthritis, who walked with aberrant walking biomechanics before treatment, failed to respond to extended-release corticosteroid treatment. • Future research should determine the mechanisms contributing to the short-term changes in gait biomechanics and physical function such as reduced inflammation.

Biomechanical assessment of alternative hand trucks for transporting heavy loads up and down stairs

Hand trucks are frequently used in delivery and moving occupations to move a variety of materials including appliances and beverages. Frequently these transport tasks involve ascending or descending stairs. This research assessed the efficacy of three commercially available alternative hand truck designs that could be used to deliver appliances. Nine experienced participants moved a 52.3 kg washing machine up and down a flight of stairs using a conventional two-wheeled hand truck, a multi-wheeled hand truck, and a two-speed powered hand truck. Electromyographic (EMG) data showed reduced right erector spinae, bilateral trapezius, and bilateral biceps 90th and 50th percentile normalized responses while ascending and descending the stairs when using the powered hand truck. The multi-wheel hand truck did not reduce EMG levels relative to the conventional hand truck. Participants, however, did express a potential concern regarding the ascent time with powered hand truck at the slower speed.

Investigating post-mild traumatic brain injury neuromuscular function and musculoskeletal injury risk: A protocol for a prospective, observational, case–controlled study in service members and active individuals

IntroductionMusculoskeletal injury (MSKI) risk is increased following mild traumatic brain injury (mTBI). Increased MSKI risk is present up to 2 years following post-mTBI return-to-duty/activity relative to both non-mTBI peers and...

Radial Wall Strain Assessment From AI-Assisted Angiography: Feasibility and Agreement With OCT as Reference Standard.

High-strain spots in coronary arteries are associated with plaque vulnerability and predict future events. Artificial intelligence currently enables the calculation of radial wall strain (RWS) from coronary angiography (RWSAngio). This study aimed to determine the agreement between novel RWSAngio and RWS derived from optical coherence tomography (OCT) followed by finite element analysis, as the established reference standard (RWSOCT). All lesions from a previous OCT study were enrolled. OCT was automatically coregistered with angiography. RWSAngio was computed as the relative luminal deformation throughout the cardiac cycle, whereas RWSOCT was analyzed using finite element analysis on OCT cross-sections at 1-mm intervals. The luminal deformation in the direction of minimal lumen diameter was used to derive RWSOCT, using the same definition as RWSAngio. The maximal RWSOCT and RWSAngio at healthy segments adjacent to the interrogated lesion were also analyzed. Finite element analysis was performed in 578 OCT cross-sections from 45 lesions stemming from 36 patients. RWSAngio showed good correlation and agreement with RWSOCT (r = 0.91; P < .001; Lin coefficient = 0.85). RWSAngio in atherosclerotic segments was significantly higher than that in healthy segments (12.6% [11.0, 16.0] vs 4.5% [2.9, 5.5], P < .001). The intraclass correlation coefficients for intra- and interobserver variability in repeated RWSAngio analysis were 0.92 (95% CI, 0.87-0.95) and 0.88 (95% CI, 0.81-0.92), respectively. The mean analysis time of RWSOCT and RWSAngio for each lesion was 95.0 ± 41.1 and 0.9 ± 0.1 minutes, respectively. Radial wall strain from coronary angiography can be rapidly and easily computed solely from angiography, showing excellent agreement with strain derived from coregistered OCT. This novel and simple method might provide a cost-effective biomechanical assessment in large populations.

Kinetic tremor analysis using wearable sensors and fuzzy inference systems in Parkinson's disease

BackgroundComputer systems for evaluating Parkinson's disease (PD) have recently increased. Many existing methods allow the quantification of tremors and extraction of some characteristics of the acquired signals by analysing manoeuvres established in the MDS-UPDRS. Some of these current methods interpret the finger-to-nose test, which includes kinetic tremors of the hands; however, an evaluation strictly based on the guidelines of the MDS Unified Parkinson's Disease Rating Scale (MDS-UPDRS) is not performed, in addition to not using additional biomechanical indicators that make more robust and accurate monitoring of the patient's evolution. New methodThe proposed method consists of a fuzzy logic system that evaluates PD patients in a range based on the MDS-UPDRS. The system evaluates by taking biomechanical features extracted from signals recorded with inertial measurement units (IMUs), which were previously processed for obtaining meaningful characteristics according to the MDS-UPDRS and other additional ones. Comparison with existing methodsIn addition to the characteristics established by the MDS-UPDRS for the classification, this method uses other procedures that were considered necessary for the achievement of an accurate evaluation, such as the amplitude of the tremors in the different stages of the finger-to-nose manoeuvre, the tremors frequency and the voluntary movement frequency. Conclusionskinetic tremors were measured based on a sensor network formed by IMUs. A Fuzzy Logic system obtains an accurate and repeatable biomechanical assessment of PD patients. This system will permit physicians to follow up on each patient with objective assessments improving medical treatments.

Non-invasive biomechanical assessment of the prolapsed vaginal wall: an explorative pilot study on cutometry and indentometry

The clinical assessment of pelvic organ prolapse (POP) and associated treatment strategies is currently limited to anatomical and subjective outcome measures, which have limited reproducibility and do not include functional properties of vaginal tissue. The objective of our study was to evaluate the feasibility of using cutometry and indentometry for non-invasive biomechanical assessment of the vaginal wall in women with POP. Both techniques were applied on the vaginal wall of 20 women indicated for surgical correction of POP stage two or higher. The primary outcome was the measurement success rate. Measurements were considered successful if biomechanical parameters were generated after a maximum of three attempts. Secondary outcomes included acquisition time, number of attempts to obtain a successful measurement, and biomechanical parameters. Measurements were successfully performed on the anterior vaginal wall of 12 women with cystocele and the posterior vaginal wall of eight women with rectocele. The success rate was 100% for both techniques and acquisition time was under 1 minute for all 20 measurements. Tissue fast elasticity of the posterior vaginal wall (rectocele) was significantly higher than that of the anterior vaginal wall (cystocele) and negatively correlated with age (r = − 0.57, P < 0.05). In women with POP, measuring the biomechanical properties of the vaginal wall using cutometry and indentometry is technically feasible. Objective evaluation of biomechanical properties may help to understand the pathophysiology behind surgical outcomes, providing an opportunity for the identification of patients at risk for (recurrent) prolapse, and individualized treatment decisions.

Exoskeletons in the Digital Era: A Way to Improve the Level of Physical Activity Among Older Citizens

Background The COVID-19 pandemic has had a negative impact on the level of physical activity among older citizens. Objective The aim of this short paper is to set focus on the potential benefits of assistive walking devices for older citizens. Methods In this feasibility study, 24 older citizens aged &gt;65 years participated in the study. The participants answered to the following questionnaires after fulfilling a consent form: Tilburg Frailty Indicator, International Physical Activity Questionnaire, and Quality of Life. Then, physiological and biomechanical assessments were made in a laboratory setting with and without wearing an exoskeleton (aLQ, IMASEN Electrical Industrial Co). The aLQ is a passive-assistive lower-limb walking exoskeleton activated by a cam spring system designed to improve gait. After the tests, the participants were asked to answer the following questions: “Do you feel the exoskeleton is helping you to walk?” and “What is your opinion on the device?”. Results The participants were community-dwelling older individuals, aged 72.6 (SD 4.5) years, and were characterized by an overall high level of physical activity of 3069 (SD 2847) metabolic equivalent–minutes per week. Their Tilburg Frailty Indicator indicated an overall frailty score of 3.5 (SD 2.5). The participants reported a Quality of Life score of 6.7 (SD 1.6) and an overall health score of 76.4 (SD 17.1). Moreover, of the 24 participants, 7 (29%) reported that carrying the tested exoskeleton did not induce any noticeable changes, and 3 (10%) reported that they walked better with the device than without. Conclusions These findings are of importance in our current digital era where the COVID-19 pandemic forced municipalities and hospitals to cancel or postpone the training and rehabilitation of older citizens, resulting in a degradation of the level of physical activity and health in general. The use of assistive walking devices can be a way to improve or maintain their level of physical activity. Future studies using a prospective design should confirm that. Conflicts of Interest None declared.

Robotic Ankle Training Improves Sensorimotor Functions in Children with Cerebral Palsy—A Pilot Study

Children with cerebral palsy (CP) have sensorimotor impairments including weakness, spasticity, reduced motor control and sensory deficits. Proprioceptive dysfunction compounds the decreased motor control and mobility. The aims of this paper were to (1) examine proprioceptive deficit of lower extremities of children with CP; (2) study improvement in proprioception and clinical impairments through robotic ankle training (RAT). Eight children with CP participated in a 6-week RAT with pre and post ankle proprioception, clinical, biomechanical assessment compared to the assessment of eight typically developing children (TDC). The children with CP participated in passive stretching (20 min/session) and active movement training (20 to 30 min/session) using an ankle rehabilitation robot (3 sessions/week over 6 weeks, total of 18 sessions). Proprioceptive acuity measured as the plantar and dorsi-flexion motion at which the children recognized the movement was 3.60 ± 2.28° in dorsiflexion and -3.72 ± 2.38° in plantar flexion for the CP group, inferior to that of the TDC group's 0.94 ± 0.43° in dorsiflexion (p = 0.027) and -0.86 ± 0.48° in plantar flexion (p = 0.012). After training, ankle motor and sensory functions were improved in children with CP, with the dorsiflexion strength increased from 3.61 ± 3.75 Nm to 7.48 ± 2.75 Nm (p = 0.018) and plantar flexion strength increased from -11.89 ± 7.04 Nm to -17.61 ± 6.81 Nm after training (p = 0.043). The dorsiflexion AROM increased from 5.58 ± 13.18° to 15.97 ± 11.21° (p = 0.028). The proprioceptive acuity showed a trend of decline to 3.08 ± 2.07° in dorsiflexion and to -2.59 ± 1.94° in plantar flexion (p > 0.05). The RAT is a promising intervention for children with CP to improve sensorimotor functions of the lower extremities. It provided an interactive and motivating training to engage children with CP in rehabilitation to improve clinical and sensorimotor performance.

Comparative Ergonomic Study Examining the Work-Related Musculoskeletal Disorder Symptoms of Taiwanese and Thai Workers in a Tape Manufacturing Factory.

This study surveyed 114 Taiwanese and 57 Thai workers in a tape manufacturing factory in Taiwan and evaluated their symptoms of work-related musculoskeletal disorder (WMSD) and associated risk factors by using the revised Nordic Musculoskeletal Questionnaire. Task-appropriate biomechanical and body load assessment tools were also employed to examine biomechanical and body load during four specified daily tasks. The results indicated that the prevalence of discomfort symptoms in any body part within one year was 81.6% for the Taiwanese workers and 72.3% for the Thai workers. The body part in which the Taiwanese workers most frequently experienced discomfort was the shoulders (57.0%), followed by the lower back (47.4%), the neck (43.9%), and the knees (36.8%); where the Thai workers most frequently experienced discomfort was the hands or wrists (42.1%), followed by the shoulders (36.8%) and the buttocks or thighs (31.6%). These locations of discomfort were associated with task characteristics. Heavy-material handling (>20 kg) more than 20 times per day was the most significant risk factor for WMSDs for both groups, and this task must thus be urgently improved. We also suggest that providing wrist braces for Thai workers may assist in alleviating their hand and wrist discomfort. The biomechanical assessment results indicated that the compression forces acting on the workers' lower backs exceeded the Action Limit standard; administrative controls must thus be instituted for two heavy-material handling tasks. In the factory, some tasks and workers' movements when completing these tasks must be assessed and improved immediately by using appropriate tools. Although the Thai workers were engaged in more physically demanding tasks, their WMSDs were milder than those of the Taiwanese workers. The results of the study can serve as references for the prevention and reduction of WMSDs in local and foreign workers in similar industries.