Relevant Body Regions Research Articles

Potential effect of pre-activated muscles under a far-side lateral impact

Objective The goal of this study is to evaluate the potential effect of muscle pre-activation under a lateral impact scenario, in this case focusing on a far-side impact, using an Active Human Body Model. Methods In total fourteen simulations were run, out of these, twelve were computed with an Active Human Body Model and two with a passive one. The models were subjected to a far-side impact scenario reaching up to 14 g’s. Two different pre-crash scenarios were analyzed with the Active Human Body Model: (1) constant velocity, and (2) braking deceleration. During the pre-crash phase a lambda control based on the muscle length computed the muscle activation. Since there is no available data concerning the neuromuscular strategy of the occupants subjected to high accelerations, six different control strategies were analyzed during the in-crash phase. Besides, rib fracture and brain injury risk were analyzed, since they are the two most relevant body regions in this simplified far-side crash scenario. Results The pre-activation of the muscles showed an effect on both the occupant kinematics and estimated injury risks. Depending on the considered muscle strategy, the head lateral excursion varied up to 75 mm, specifically for the scenario with constant velocity. Moreover, the rib fracture probability and the brain injury indicator revealed higher injury risks for the passive Human Body Model. When applying the constant velocity during pre-crash, the fracture probability for two or more ribs ranged from 9.91 to 46.06% for the Active Human Body Model, whereas it reached 84.3% for the passive model. The brain injury indicator was reduced by about 10% when using the active model compared to the passive one. Conclusions The numerical results show that the pre-activation of the muscles affects the kinematic and injury outcomes in car crashes. In this study, six muscular control strategies have been proposed. The two muscular controls that may be most realistic are: constant activation after the in-crash phase starts, by trying to hold the position prior to the crash, or no stimulation, by not responding to the upcoming in-crash event.

Role of the Cadaver Lab in Lymphatic Microsurgery Education: Validation of a New Training Model

Background Microsurgical transplantation of vascularized lymph nodes (VLNT) or lymphatic vessels (VLVT) alongside derivative lymphaticovenous procedures are promising approaches for treatment of lymphedema. However, clinically relevant training models for mastering these techniques are still lacking. Here we describe a new training model in human cadaver and validate its use as training tool for microsurgical lymphatic reconstruction. Methods 10 surgeons with previous exposure to microsurgery were trained in a controlled environment. Lymphatic vessel mapping and dissection in 4 relevant body regions, harvesting of five different VLNTs and one VLVT were performed in 5 fresh-frozen cadavers. The number of lymphatic vessels and lymph nodes for each VLNT were recorded. Finally, the efficacy of this model as training tool was validated using the Dundee Ready Education Environment Measure (DREEM). Results The average cumulative DREEM score over each category was 30,75 (max = 40) while individual scoring for each relevant category revealed highly positive ratings from the perspective of teaching (39,3), training 40,5 (max = 48) and self perception of the training 30,5 (max = 32) from all participants. The groin revealed the highest number of lymphatic vessels (3.2 ± 0.29) as all other regions on the upper extremity, while the gastroepiploic VLNT had the highest number of lymph nodes (4.2 ± 0.37). Conclusions This human cadaver model represents a new, reproducible “all-in-one” tool for effective training in lymphatic microsurgery. Its unique diligence in accurately reproducing human lymphatic anatomy, should make this model worth considering for each microsurgeon willing to approach lymphatic reconstruction.

Smart heating panels to increase thermal comfort and efficiency.

The increasing electrification poses new challenges with respect to thermal comfort in vehicle passenger cabins. While conventional air heating with electric heaters is technically possible, it causes significant reductions in the electric driving range. Two contradicting objectives are to be achieved: Fast heat up to provide thermal comfort and high energy efficiency to maximize the driving range under all conditions. This apparent area of conflict can be eased by the usage of low temperature radiation reducing the energy intensive heat up of the cabin air. In order to provide high energy efficiency, the emitted radiation should mostly be directed towards relevant body regions of the passengers, resulting in the necessity to redesign the passenger cabin. A novel approach to redesign and optimize the dashboard and a resulting radiation heating system are presented. In order to reduce computational effort of such an optimization, the complex three-dimensional geometry is sliced into simplified two-dimensional regions which are considered individually. The resulting heating system has been manufactured and integrated into a class A vehicle. Objective thermal comfort measurements as well as subjective comfort ratings have been conducted to validate the simulative approach and the resulting energy savings of approximately 30 %. The developed approach to achieve a fast time to comfort as well as an increased energy efficiency shows promising results as the heating system based on it cuts performs well considering objective and subjective measurements.

Whole-body computed tomography in trauma patients: optimization of the patient scanning position significantly shortens examination time while maintaining diagnostic image quality.

BackgroundThe study was conducted to compare examination time and artifact vulnerability of whole-body computed tomographies (wbCTs) for trauma patients using conventional or optimized patient positioning.Patients and methodsExamination time was measured in 100 patients scanned with conventional protocol (Group A: arms positioned alongside the body for head and neck imaging and over the head for trunk imaging) and 100 patients scanned with optimized protocol (Group B: arms flexed on a chest pillow without repositioning). Additionally, influence of two different scanning protocols on image quality in the most relevant body regions was assessed by two blinded readers.ResultsTotal wbCT duration was about 35% or 3:46 min shorter in B than in A. Artifacts in aorta (27 vs 6%), liver (40 vs 8%) and spleen (27 vs 5%) occurred significantly more often in B than in A. No incident of non-diagnostic image quality was reported, and no significant differences for lungs and spine were found.ConclusionAn optimized wbCT positioning protocol for trauma patients allows a significant reduction of examination time while still maintaining diagnostic image quality.

Towards a body hair atlas of women of caucasian ethnicity.

A preliminary study was conducted in 17 female volunteers (mean age 29.8 years) to gain deeper insights into the characteristics of terminal Caucasian female body hair of different body parts. The focus on Caucasian women was driven by the high number of different scalp hair phenotypes in this ethnicity and intended to identify relevant differences between body areas to improve body hair removal approaches. Multiple growth parameters and structural parameters were assessed for hair on the upper arm, forearm, upper leg, lower leg, axilla and intimate area and compared to scalp data. In particular, macroscopic and much less microscopic or hair surface properties differ strikingly in the investigated body areas. Hair density on the body is much lower than on scalp with the highest hair density in the axilla and intimate area. Multihair follicular units are described for scalp but were also found to a smaller proportion in the axilla and the intimate area. Substantial percentages of hair triplets are only found on the scalp and intimate area. Hair diameter is highest in the intimate area, followed by axillary and lower leg hair and correlates with a faster hair growth rate. The angle of emerging hair is smallest in the intimate area, axilla and on the lower leg. Hair shafts on the lower leg and in the axilla have most overlapping cuticle layers, but independent of body region, no significant differences in the mean thickness of cuticle layers were detectable. In addition, no differences were found in the mean distance between cuticle layer edges along the hair shaft and the hair surface roughness. Hair on the scalp, forearm, upper arm and upper leg had an almost round shape, whereas hair of the lower leg, intimate area and axilla had more elliptical shape. Hairs on the arm showed the highest luminance values and no visible medulla. The darkest hairs were in the axilla and intimate area containing the highest level of visible medulla in hair shafts. To our knowledge, this is the first systematic study comparing terminal hair properties in all cosmetically relevant body regions in Caucasian women.

WERA: an observational tool develop to investigate the physical risk factor associated with WMSDs.

This paper describes the development of the Workplace Ergonomic Risk Assessment (WERA) for investigating the physical risk factor associated with work-related musculoskeletal disorders (WMSDs). The initial development of WERA tool involved the following procedures: (1) first stage, development of WERA prototype from literature review, (2) second stage, evaluation of the psychometric properties including (a) validity trials and (b) reliability and usability trials. In the validity trials, the relationship of the individual WERA body part scores to the development of pain or discomfort is statistically significant for the wrist, shoulder and back regions. It shows that the WERA assessment provided a good indication of work-related musculoskeletal disorders which might be reported as pain, ache or discomfort in the relevant body regions. In the reliability trials, the results of inter-observer reliability shows that moderate agreement among the observers while from the feedback questionnaire survey about the usability of WERA tool, all participants including expert and management teams agreed that the prototype of WERA tool was easy and quick to use, applicable to workplace assessment for the wide range of job/task and valuable at work. It was confirmed that there was no need of training required to do WERA assessment. Therefore, the WERA assessment has been designed for easy and quick use, and for those who are trained to use it do not need previous skills in observation techniques although this would be an advantage. As WERA is a pen and paper technique that can be used without any special equipment, WERA assessment can be done in any space of workplaces without disruption to the task that have been observed.

Physical Inactivity and Pain in Older Men and Women with Hip Fracture History

Hip fracture patients often suffer from pain for several months after surgery. This may lead to physical inactivity and subsequent mobility limitation and disability. The purpose of this study was to investigate the association between severe musculoskeletal pain and the level of physical activity in older people with a history of hip fracture. Data were collected from 60- to 85-year-old (n = 78) community-dwelling people, 0.7–7.5 years after hip fracture. Physical activity was assessed with the Yale Physical Activity Survey (YPAS). According to the YPAS summary index distribution, the participants were divided into the physically inactive and physically active groups. Musculoskeletal pain in the lower back, hip or knee region was assessed by the Visual Analog Scale. Pain was defined as severe pain if the subject rated the pain 66 mm or over (upper third of the scale) in at least one of the relevant body regions in the lower body. Thirty-three subjects (42%) experienced severe pain in the lower body, of whom 23 (70%) reported severe pain in the operated hip. Twenty-three patients (30%) used pain medication prescribed by a physician. The level of musculoskeletal pain was significantly higher in the physically inactive (62%) than in the physically active (31%) group (p = 0.011). Logistic regression analysis showed that people with severe pain had over three times (OR: 3.5, 95% CI: 1.30–9.39) the risk for physical inactivity compared to those with less or no pain. Multivariate adjustments for balance confidence, time since fracture, number of chronic diseases and type of surgery did not materially change the estimate (OR: 3.0, 95% CI: 1.00–9.30). Pain is an important associated factor of physical inactivity in older people with a hip fracture history. Pain management may be important in restoring and sustaining the level of physical activity after hip fracture. Further prospective and experimental studies are, however, needed to explore the causality between pain and physical activity as well as the role of pain management and physical activity interventions in preventing mobility limitation and disability among older people recovering from hip fracture.

Looking for Ms. Right: Allocating Attention to Facilitate Mate Choice Decisions

Through various signals, the human body provides information that may be used by receivers to make decisions about mate value. Here, we investigate whether there exists a complementary psychological system designed to selectively attend to these signals in order to choose, and direct effort toward the acquisition of, a potential mate. We presented young men with three images of the same woman (six women in total) simultaneously, varying the waist-to-hip ratio (WHR) of each image while holding other traits constant. While participants chose their preferred image, we monitored visual attention using an infrared eye-tracker. We found that participants focused their attention selectively on body regions known to provide reproductive information in a manner consistent with the research hypothesis: Reproductively relevant body regions, especially the head and breasts, received the most visual attention. Likewise, images with lower WHRs and reproductively relevant regions in images with lower WHRs received the most visual attention and were chosen as most attractive. Finally, irrespective of WHR size, participants fixated more often and for longer durations on the images that they selected as most attractive.

Provocative cervical discography symptom mapping

Background context In a small prospective study assessing 10 symptomatic and 10 asymptomatic subjects, Schellhas et al. compared cervical discography to magnetic resonance imaging. Within that study he reported on the distribution of pain for the C3–C4 to C6–C7 levels. Four years later, Grubb and Ellis reported retrospective data from his 12-year experience using cervical discography from C2–C3 to C7–T1 in 173 patients. To date, no large prospective study defining pain referral patterns for each cervical disc has been performed. Purpose To conduct a prospective visual and statistical descriptive study of pain provocation of a cohort of subjects undergoing cervical discography. Study design/setting Prospective multicenter descriptive study. Methods Pain referral maps were generated for each disc level from patients undergoing cervical discography with at least two levels assessed. If concordant pain was reproduced in a morphologically abnormal disc, the subject immediately completed a pain diagram. An independent observer interviewed the subject and recorded the location of provoked symptoms. Visual data were compiled using a body sector bit map, which consisted of 48 clinically relevant body regions. Visual maps with graduated color codes and frequencies of symptom location at each cervical disc level were generated. Results A total of 101 symptom provocation maps were recorded during cervical discography on 41 subjects. There were10 at C2–C3, 19 at C3–C4, 27 at C4–C5, 27 at C5–C6, 16 at C6–C7 and 2 at C7–T1. Predominantly unilateral symptoms were provoked just as often as bilateral symptoms. The C2–C3 disc referred pain to the neck, subocciput and face. The C3–C4 disc referred pain to the neck, subocciput, trapezius, anterior neck, face, shoulder, interscapular and limb. The C4–C5 disc referred pain to the neck, shoulder, interscapular, trapezius, extremity, face, chest and subocciput. The C5–C6 disc referred pain to the neck, trapezius, interscapular, suboccipital, anterior neck, chest and face. The C6–C7 disc referred pain to the neck, interscapular, trapezius, shoulder, extremity and subocciput. At C7–T1 we produced neck and interscapular pain. Visual maps with graduated color codes and frequencies of symptom location at each cervical disc level were generated. Conclusions In conclusion, these results confirm the observations of prior investigators that cervical internal disc disruption can elicit axial and peripheral symptoms. The particular patterns of pain generation allow the discographer to preprocedurally anticipate disc levels to assess. With these data, the number of disc punctures that are required can be limited rather than routinely assessing all cervical discs.

Symptom provocation of fluoroscopically guided cervical nerve root stimulation. Are dynatomal maps identical to dermatomal maps?

This prospective study consisted of mechanical stimulation of cervical nerve roots C4 to C8 in patients with cervical radicular symptoms undergoing diagnostic selective nerve root block. To document the distribution of pain and paresthesias that result from stimulation of specific cervical nerve roots and compare that distribution to documented sensory dermatomal maps. Cervical dermatomes were first studied in the late 19th century. The results of those studies underpin current clinical decision making for patients with neck and arm pain. However, it has been observed that patients with radicular symptoms may have cervical pathology by radiographic imaging that is not corroborative, or have imaging studies that suggest a lesion at a level other than the one suggested by the patient's dermatomal symptoms. These observations may suggest that cervical dermatomal mapping is inaccurate or the distribution of referred symptoms (dynatome) from cervical root irritation is different than the sensory deficit outlined by dermatomal maps. Inclusion criteria consisted of consecutive patients undergoing fluoroscopically guided diagnostic cervical selective nerve root blocks from C4 to C8. Immediately preceding contrast injection, mechanical stimulation of the root was performed. An independent observer interviewed and recorded the location of provoked symptoms on a pain diagram. Visual data was subsequently compiled using a 793 body sector bit map. Forty-three clinically relevant body regions were defined on this bit map. Frequencies of symptom provocation and likelihood of symptom location from C4 to C8 stimulation of each nerve root were generated. One hundred thirty-four cervical nerve root stimulations were performed on 87 subjects. There were 4 nerve root stimulations at C4, 14 at C5, 43 at C6, 52 at C7, and 21 at C8. Analyzing the frequency of involvement of the predetermined clinically relevant body regions either individually or in various combinations yielded more than 1,000 bits of data. Although the distribution of symptom provocation resembled the classic dermatomal maps for cervical nerve roots, symptoms were frequently provoked outside of the distribution of classic dermatomal maps. The current study demonstrates a distinct difference between dynatomal and dermatomal maps.