Comparison of spatial summation properties at different body sites

2017 ◽  
Vol 17 (1) ◽  
pp. 126-131 ◽  
Author(s):  
Maleea D. Holbert ◽  
Ashley Pedler ◽  
Danny Camfermann ◽  
Daniel S. Harvie

AbstractBackground and aimsThe nociceptive system appears to have evolved a range of protective characteristics that are of great interest in understanding both acute and chronic pain. Spatial summation is one important characteristic, whereby increasing area of a stimulus, or distance between multiple stimuli, results in more intense pain—not only greater area of pain. One of the mysteries of chronic pain is why spinal pain is so prevalent relative to pain at other sites. Since pathological tissue models have failed to fully explain spinal pain, we theorized that body region specific differences in sensory processing—such as a greater propensity for spatial summation—may help to explain its vulnerability. We aimed to examine this by comparing the properties of summation at different body parts: the dorsal forearm, neck, and back.MethodsSpatial summation of pain was investigated using noxious intra-dermal electrical stimuli in healthy pain-free adults (14 males, 6 females), and the perceived pain intensity was rated on a 0-100 pain scale. Area-based stimulation was investigated by doubling the stimulation area with the addition of a second electrode placed adjacent to the first. Distance-based summation was investigated by randomly varying the separation distance between paired noxious electrical stimuli at separations of 0,10,15, and 20 cm.ResultsThis study demonstrated that the properties of area- and distance-based summation are uniform across the neck, back, and forearm in healthy adults. Spatial summation of pain was also found to be greatest at 15- and 20-cm paired separations for all body regions tested, confirming that noxious information can be integrated over an extensive anatomical area.ConclusionData from this investigation refutes the thesis that spatial summation of pain may be a contributing factor for the reported difference in chronicity rates between spinal and peripheral sites. It remains, however, a potentially important mechanism by which noxious inputs from multi-level pathology might integrate and contribute to pain.ImplicationsWhile data from this project suggest that there are no regional differences in the properties of spatial summation of noxious stimuli, regional differences in other characteristics of the nociceptive system may yet provide insight into why some spinal pain is so highly prevalent; nociceptive distance-based summation may be highly relevant where two or more conditions co-exist in close proximity.

2019 ◽  
Vol 40 (2) ◽  
pp. 149-162 ◽  
Author(s):  
Andre C. Bruinjé ◽  
Mauricio O. Moura ◽  
Bruno S. Maggi ◽  
Vinicius A. São-Pedro ◽  
Daniel M.A. Pessoa ◽  
...  

Abstract Animal colouration plays a key role in inter and intraspecific interactions, pre-eminently in mate signalling. When multiple types of colouration occur within sexes it is possible that they show alternative reproductive strategies. In lizards, most colouration studies do not incorporate how colour is perceived by conspecifics. Here, we used unbiased colour analysis methods (spectrophotometry and visual modelling) to test for sexual dimorphism and within male dichromatism in the Striped Lava Lizard. We found that males express two distinct colourations that are different from females in several dorsal and ventral body regions. Our results showed UV reflection at the throat, an important body region for signalling. Ventral patches, the coloured badge seen in adult males of Tropidurus spp., have two distinct colour classes within males (Y and B males). Morphs are best discriminated by blue and yellow chroma, and brightness. Body size had little influence on colouration, suggesting that colour may be linked to inheritance rather than growth. Our study clearly shows sexual dichromatism and the existence of colour morphs in this species. Moreover, morph differences in colouration are perceptible by conspecifics. These differences are not only between ventral patches, but also in other body parts such as the dorsum, previously considered as cryptic by human observers. We suggest that colouration at the ventral patches and throat might play a role in intraspecific interactions. Patches increase colour intensity during breeding season and are likely to be costly by pigment-based expression, whereas throat’s UV reflection might have a cost infringed by conspicuousness.


Author(s):  
Hyun Chul Jung ◽  
Hanna Straltsova ◽  
Michael A. Woodgate ◽  
Kyung-Min Kim ◽  
Jung-Min Lee ◽  
...  

This study examined the rate of injuries and chronic pain in collegiate water-ski athletes as a preliminary study. We also compared the mechanics and cause of injuries by the level of water-skiing experiences. A total number of 96 collegiate water-ski athletes, aged 21.4 ± 2.23 years, participated in the study. An off-line questionnaire was distributed at the collegiate tournaments in the United States. The questionnaire consisted of 20 questions, including demographic information, body region and type of injuries, mechanics and cause of injuries, chronic pain and pain management. A Chi-squared test was used to examine the differences in injury rates by sex and the level of experiences (beginner: <5 years, intermediate: 5–10 years, advanced: <10 years). The significance level was set at ≤0.05. A total of 336 water skiing-related injuries were observed from 96 participants. The ankle/feet, knee, and head/neck regions were the most common body regions injured, representing 26.5, 16.7, and 15.8%, respectively. Female athletes were more likely to have nerve injuries than male athletes (p = 0.039). The intermediate athletes were more likely to have trunk (p = 0.047) and upper extremity (p = 0.042) injuries than beginner athletes, and the beginner athletes had less joint/ligament (p = 0.001) and bone injury (p = 0.010) compared to the advanced athletes. Torsion/twisting (32.8%) and deceleration (26.9%) were the most common mechanism of injury. Beginner athletes experienced injuries more due to insufficient skill (p = 0.03), while the advanced athletes were likely to have more injuries by the loss of control (p = 0.01). Collegiate athletes had higher rates of chronic pain in the trunk (42.7%) and skeletal muscle (43.8%), and they participated in stretching/exercise (40.8%) and massage/form rolling (29.6%) to manage their chronic pain. The present study revealed that injury rates in males and females were 49.7% and 50.2%, respectively. Female athletes were more likely to have a nerve injury than male athletes. The mechanics and cause of injuries were different by the level of experiences where different training approaches may be required to minimize the injuries. Additionally, the strength and conditioning program that is systematically designed for core strength is needed to eliminate chronic trunk pain in collegiate water-skiing athletes.


2015 ◽  
Vol 8 (2) ◽  
pp. 237-282 ◽  
Author(s):  
JOSITA C. MAOUENE ◽  
NITYA SETHURAMAN ◽  
MOUNIR M. MAOUENE ◽  
SANGO OTIENO

abstractPrior work on argument structure development has shown connections between abstract verb meaning and argument structure; neuroimaging and behavioral studies have shown connections between verb meaning and body effectors. Here we examine the contingencies between verbs, their most likely body region pairing, and argument structure. We ask whether the verbs used in six common syntactic frames are specifically linked to one of three main regions of the body:head, arm, leg.The speech of 20-month-olds (N= 67), 28-month-olds (N= 27), and their mothers (N= 54) (CHILDES: MacWhinney, 2000) was examined for the use of early-learned verbs (MCDI: Fenson, Dale, Reznick, Bates, Thal, & Pethick, 1994). In total, 89 verb types in 3321 utterances were coded for their associations with thehead, arm, andlegbody regions (associations taken from Maouene, Hidaka, & Smith, 2008). Significant non-random relations are found both overall and for each age group in analyses using multiple chi-square tests of independence and goodness-of-fit. These results are discussed in terms of their relevance for both argument structure development and embodied cognition, as evidence supporting a developmental path that has not been previously examined, in which the infant can use early and concrete perception-action information to learn later abstract syntactic achievements.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
František Vejmělka ◽  
Jan Okrouhlík ◽  
Matěj Lövy ◽  
Gabriel Šaffa ◽  
Eviatar Nevo ◽  
...  

AbstractThe relatively warm and very humid environment of burrows presents a challenge for thermoregulation of its mammalian inhabitants. It was found that African mole-rats dissipate body heat mainly through their venter, and social mole-rats dissipate more body heat compared to solitary species at lower temperatures. In addition, the pattern of the ventral surface temperature was suggested to be homogeneous in social mole-rats compared to a heterogeneous pattern in solitary mole-rats. To investigate this for subterranean rodents generally, we measured the surface temperatures of seven species with different degrees of sociality, phylogeny, and climate using infrared thermography. In all species, heat dissipation occurred mainly through the venter and the feet. Whereas the feet dissipated body heat at higher ambient temperatures and conserved it at lower ambient temperatures, the ventral surface temperature was relatively high in all temperatures indicating that heat dissipation to the environment through this body region is regulated mainly by behavioural means. Solitary species dissipated less heat through their dorsum than social species, and a tendency for this pattern was observed for the venter. The pattern of heterogeneity of surface temperature through the venter was not related to sociality of the various species. Our results demonstrate a general pattern of body heat exchange through the three studied body regions in subterranean rodents. Besides, isolated individuals of social species are less able to defend themselves against low ambient temperatures, which may handicap them if staying alone for a longer period, such as during and after dispersal events.


Pain Medicine ◽  
2021 ◽  
Author(s):  
Nick Christelis ◽  
Brian Simpson ◽  
Marc Russo ◽  
Michael Stanton-Hicks ◽  
Giancarlo Barolat ◽  
...  

Abstract Objective For many medical professionals dealing with patients with persistent pain following spine surgery, the term failed back surgery syndrome (FBSS) as a diagnostic label is inadequate, misleading and potentially troublesome. It misrepresents causation. Alternative terms have been suggested but none has replaced FBSS. The International Association for the Study of Pain (IASP) published a revised classification of chronic pain, as part of the new International Classification of Diseases (ICD-11), which has been accepted by the World Health Organization (WHO). This includes the term Chronic pain after spinal surgery (CPSS), which is suggested as a replacement for FBSS. Methods This article provides arguments and rationale for a replacement definition. In order to propose a broadly applicable yet more precise and clinically informative term, an international group of experts was established. Results 14 candidate replacement terms were considered and ranked. The application of agreed criteria reduced this to a shortlist of four. A preferred option – Persistent spinal pain syndrome – was selected by a structured workshop and Delphi process. We provide rationale for using Persistent spinal pain syndrome and a schema for its incorporation into ICD-11. We propose the adoption of this term would strengthen the new ICD-11 classification. Conclusions This project is important to those in the fields of pain management, spine surgery and neuromodulation, as well as patients labelled with FBSS. Through a shift in perspective it could facilitate the application of the new ICD-11 classification and allow clearer discussion amongst medical professionals, industry, funding organisations, academia, and the legal profession.


2019 ◽  
Vol 33 (6) ◽  
pp. 494-503
Author(s):  
Ekarat Sombatsawat ◽  
Titaporn Luangwilai ◽  
Parichat Ong-artborirak ◽  
Wattasit Siriwong

Purpose The purpose of this paper is to explore the prevalence of musculoskeletal disorders (MSDs) and determine factors influencing MSDs among rice farmers. Design/methodology/approach A cross-sectional study was carried out among 156 rice farmers from 14 villages in Tarnlalord sub-district, Phimai district, Nakhon Ratchasima province, Thailand, from February 2017 to March 2017. Face-to-face interviews, including demographics, work characteristics and musculoskeletal pain, were conducted using a modified standardized Nordic questionnaire. Findings The results revealed that both 78 males and 78 females participated in the study to which the average of age and body mass index (BMI) was 45.5±11.4 years and 24.9±4.0 kg/m2, respectively. All rice farmers reported MSDs in at least one body region during the six months preceding the interview. The highest prevalence of MSDs showed 86.5 percent in the lower back area, followed by 85.9 percent in the neck, and 80.7 percent in the shoulders. The analysis of binary logistic regression and Spearman’s rank correlation showed that factors such as gender, age, BMI, work experience and farm size influence MSDs’ occurrence, and pain severity in one or more body regions (p < 0.05). Originality/value Musculoskeletal injuries are a significant health problem in rice farmers. The study indicated that appropriate agricultural practices such as working posture, equipment size selection and carrying loads should be recommended to prevent MSDs. Thus, the occupational health and safety services in agricultural workers are needed.


2018 ◽  
Vol 4 (12) ◽  
pp. eaau6252 ◽  
Author(s):  
Yao Guo ◽  
Weixuan Zhang ◽  
Hanchun Wu ◽  
Junfeng Han ◽  
Yongliang Zhang ◽  
...  

The edges of layered materials have unique properties that substantially differ from the body regions. In this work, we perform a systematic Raman study of the edges of various layered materials (MoS2, WS2, WSe2, PtS2, and black phosphorus). The Raman spectra of the edges feature newly observed forbidden Raman modes, which are originally undetectable from the body region. By selecting the edge type and the polarization directions of the incident and scattered light, all forbidden Raman modes are distinctly detected. Optical simulations show that the edges of layered materials drastically distort the electromagnetic fields of both the incident and scattered light, so that the light interacts with the edges in a distinct way, which differs from its interactions with the body regions.


Author(s):  
K. Saraswathi Krishnan ◽  
Gunasunderi Raju ◽  
Omar Shawkataly

Purpose—This study aimed to estimate the prevalence and risk factors of MSD pain in various anatomical regions among nurses. Method—A cross-sectional study involving a self-administered questionnaire by registered nurses with clinical experience. Data was collected using convenience sampling after obtaining informed consent. The results were drawn from a total of 300 nurses. Results—The nurses presented with occasional mental exhaustion (44.3%) and often physical exhaustion (44.0%). Almost all (97.3%) the nurses complained of having work-related pain during the last 12 months. Body parts with the most pain were the lower back (86.7%), ankles (86.7%), neck (86.0%), shoulders (85.0%), lower legs (84.7%) and upper back (84.3%). The pain frequency was rated as occasional pain for the neck and upper back, pain was often felt for the rest of the parts. Nurses complained of severe pain in the lower back (19.7%), right shoulder (29.7%) and left shoulder (30.3%). The frequency of having musculoskeletal symptoms in any body region was increased with age, lower education level, female gender, high BMI, job tenure and lifestyle. Conclusions—Nurses’ WRMSD complaints should be taken seriously to curb further risk and musculoskeletal hazards.


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