The relationship between subtalar and knee joint function as a possible mechanism for running injuries

The purposes of the study were: (1) to evaluate the effects of different surfaces on the relationship between subtalar and knee joint function, and (2) to examine/explore alternative approaches to the evaluation of these relationships. Five subjects ran under four different surface conditions of various hardness, while both rear and sagittal view kinematic data were collected (200 Hz). Critical parameters describing the knee angle and rearfoot motion were examined in conjunction with a curve analysis technique which incorporated slope differences and curve correlations. A repeated measure ANOVA design (surface × subject) was used along with single subject procedures. The results of the study support a strong inter-relationship between pronation and knee joint function via tibial rotation and underlined it as a possible mechanism for injury. Moreover, discrete point analysis might not be the most appropriate methodology for evaluating dynamic functions such as rearfoot motion and knee angle. Extreme methodological care must be exercised when evaluating these functions to avoid oversmoothing and/or masking correlations and differences due to differential subject responses and individual variability. The fact that increased impact force facilitated timing discrepancies between subtalar and knee joint function resulting in a transition of the pronation curve from a unimodal to bimodal configuration, is hypothesized as a possible explanation to better understand the inter-relationships among these lower extremity functions and their relationship to running injuries

Performance Accomodation to Midsole Hardness During Running

The effects of shoe hardness on impact force characteristics during running were elevated using both a group and single subject analysis approach. It was hypothesized that non-significant shoe effects previously reported could have resulted from the experimental design and analysis procedures employed. The present study evaluated 18 runners using a single subject procedure in addition to a group design (Shoe Condition X (Subject X Shoe Hardness)). ANOVA analyses identified significant differences (p \u3c 0.05) between mean impact forces for the soft shoe condition and mean maximum knee flexion angles for the hard shoe condition. Individual subject analyses identified no significant (p \u3c0:05) impact force differences for eight subjects while I 0 subjects exhibited significant differences. A significant correlation coefficient of -0.59 between impact force and maximum knee flexion suggested that some accommodation took place on average but the extent varied among subject. Post-hoc group analyses identified a relationship (r = 0.59) between impact tester results and impact forces for one subgroup of subjects.The results support the hypothesis that subjects can and do respond differently to the same perturbation ·and that these differential responses can compromise group analysis results

KINEMATIC AND TEMPORAL CHARACTERISfICS OF SELECTED JUDO HIP THROWS

The sport of judo, developed In 1882 in Japan by Jigoro Kano, is a refined version of the ancient martial art of jujitsu. Typically when one envisions martial arts, the mental image includes kicks, punches, and other striking techniques. The sport of judo involves none of these, but does permit the use of throwing techniques, mat work similar to wrestling, strangle holds and joint locks at the elbow. Despite its original role as a martial art, judo as practiced today is essentially the highest form of wrestling practiced anywhere in the world (Reay &Hobbs, 1979)

Asynchrony between subtalar and knee joint function during running

Purpose: It has been suggested that during running proper coordination between subtalar joint pronation/supination and knee joint flexion/extension via tibial rotation is important to attenuate ground reaction impact forces (GRIF). Lack of coordination may produce over time a wide range of injuries. The goal of this study was to investigate the relationship between subtalar pronation/supination and knee flexion/extension with GRIF increases during distance running. Methods: Eight subjects ran under different speeds (a self-selected pace, 10% faster, 10% slower, and 20% faster) and over different obstacle heights (5%, 10%, and 15% of their standing height) on their self-selected pace. Sagittal, rear-view kinematic, and GRIF data were collected. The biomechanical results were also compared with data from a clinical evaluation of the subjects. Results: Speed changes and obstacle heights produced increases in GRIF and differences between rearfoot and knee angular velocities. The higher the obstacle and the faster the speed, the greater the GRIF and the greater the velocity differences. A change of the rearfoot angle curve from a unimodal (one minimum) to a bimodal (two minimums) parabolic configuration was also observed. The appearance of the second minimum was attributed to a lateral deviation of the tibia as a rebound effect due to the increased impact with the ground. The velocity differences between the actions of the subtalar and the knee joint, which in essence capture the antagonistic nature of their relationship, produced the highest correlation with the clinical evaluation. Conclusions: It was suggested that a possible mechanism responsible for various running injuries could be lack of coordination between subtalar and knee joint actions. This mechanism may have potential for predicting runners with susceptibility to injury

Interactive effects between group and single-subject response patterns

A two-part study was undertaken to investigate the effects of movement experiences on lower extremity function during impact activities. Group and single-subject performances were evaluated for a total of 12 male volunteers during landing (Study I) and running (Study II) activities. Standard biomechanical techniques were used to obtain kinematic (200 Hz) and kinetic (1000 Hz) data during soft, normal and stiff-knee landings (Study I) and for under, normal, and over-stride running (Study II). Performance trials were tested for normality, condition differences were documented and multiple regression models were computed to predict the first (F1) and second (F2) maximum vertical forces during landing and the maximum impact force (IF) during running. Results of the study identified condition differences with no deviations from normality, thereby achieving the goal of increasing performance heterogeneity to benefit the modeling procedures. Group regression model results for F1, F2 and IF each identified a single predictor variable that accounted for 74.7, 98.6 and 81.6% explained variance (EV), respectively. Single-subject predictors and EV values varied and demonstrated a number of different strategies. The group models were not representative of any of the individual subjects\u27 performances and indicate that group models can describe a mythical average performer. These results suggest that researchers must be cautious when evaluating group performance patterns

A dynamical systems investigation of lower extremity coordination during running over obstacles

Objective. To investigate intralimb coordination during running over a level surface and over obstacles of three different heights. Design. The phasing relationships between the foot and leg motions in the frontal plane, and the shank and thigh motions in the sagittal plane were used to compare patterns of coordination. Background. The coordinated actions of lower extremity segments are necessary to absorb the impact forces generated during running. The behavioral patterns of these segments can be studied under changing task demands using analysis techniques from the Dynamical Systems Theory. Methods. Ten subjects ran at their self-selected pace under four conditions: over a level surface and over obstacles of different heights (5%, 10%, 15% of their standing height). A force platform was used to record impact forces during landing after obstacle clearance, while kinematics were collected using a two-camera system. Results. The increases in obstacle height resulted in significant changes in impact forces (34% increase between the two extreme conditions) and more in-phase relationships between the segments during early stance. No changes were observed in the variability of the phasing relationships. Conclusions. The coordination changes observed might be compensatory strategies aimed to reduce forces and potential injury. However, since the impact forces still increased significantly, it is also possible that the observed changes might be at-risk movement patterns predisposing runners to injury. Relevance Tools from the Dynamical Systems Theory, such as intralimb coordination, can be used as a way to evaluate running mechanics so that comparisons can be made to various patient populations in subsequent studies. This approach might be a viable alternative to examine questions in therapeutics

The MyD88+ phenotype is an adverse prognostic factor in epithelial ovarian cancer

The prognosis of epithelial ovarian cancer is poor in part due to the high frequency of chemoresistance. Recent evidence points to the Toll-like receptor-4 (TLR4), and particularly its adaptor protein MyD88, as one potential mediator of this resistance. This study aims to provide further evidence that MyD88 positive cancer cells are clinically significant, stem-like and reproducibly detectable for the purposes of prognostic stratification. Expression of TLR4 and MyD88 was assessed immunohistochemically in 198 paraffin-embedded ovarian tissues and in an embryonal carcinoma model of cancer stemness. In parallel, expression of TLR4 and MyD88 mRNA and regulatory microRNAs (miR-21 and miR-146a) was assessed, as well as in a series of chemosensitive and resistant cancer cells lines. Functional analysis of the pathway was assessed in chemoresistant SKOV-3 ovarian cancer cells. TLR4 and MyD88 expression can be reproducibly assessed via immunohistochemistry using a semi-quantitative scoring system. TLR4 expression was present in all ovarian epithelium (normal and neoplastic), whereas MyD88 was restricted to neoplastic cells, independent of tumour grade and associated with reduced progression-free and overall survival, in an immunohistological specific subset of serous carcinomas, p<0.05. MiR-21 and miR-146a expression was significantly increased in MyD88 negative cancers (p<0.05), indicating their participation in regulation. Significant alterations in MyD88 mRNA expression were observed between chemosensitive and chemoresistant cells and tissue. Knockdown of TLR4 in SKOV-3 ovarian cells recovered chemosensitivity. Knockdown of MyD88 alone did not. MyD88 expression was down-regulated in differentiated embryonal carcinoma (NTera2) cells, supporting the MyD88+ cancer stem cell hypothesis. Our findings demonstrate that expression of MyD88 is associated with significantly reduced patient survival and altered microRNA levels and suggest an intact/functioning TLR4/MyD88 pathway is required for acquisition of the chemoresistant phenotype. Ex vivo manipulation of ovarian cancer stem cell (CSC) differentiation can decrease MyD88 expression, providing a potentially valuable CSC model for ovarian cancer

The scope for pavement porters: addressing the challenges of last-mile parcel delivery in London

The UK parcel sector generated almost £9 billion in revenue in 2015, with growth expected to increase by 15.6% in 2019 and is characterized by many independent players competing in an ‘everyone-delivers-everywhere’ culture leading to much replication of vehicle activity. With road space in urban centers being increasingly reallocated to pavement widening, bus and cycle lanes, there is growing interest in alternative solutions to the last-mile delivery problem. We make three contributions in this paper: firstly, through empirical analysis using carrier operational datasets, we quantify the characteristics of last-mile parcel operations and demonstrate the reliance placed on walking which can make up over 60% of the round time; secondly we introduce the concept of ‘portering’ where vans rendezvous with porters who operate within specific ‘patches’ to service consignees on-foot, potentially saving 86% in driving distance on some rounds; finally, we highlight the wider practical issues and optimization challenges associated with operating driving and portering rounds in inner urban areas

The MyD88+ phenotype is an adverse prognostic factor in epithelial ovarian cancer

The prognosis of epithelial ovarian cancer is poor in part due to the high frequency of chemoresistance. Recent evidence points to the Toll-like receptor-4 (TLR4), and particularly its adaptor protein MyD88, as one potential mediator of this resistance. This study aims to provide further evidence that MyD88 positive cancer cells are clinically significant, stem-like and reproducibly detectable for the purposes of prognostic stratification. Expression of TLR4 and MyD88 was assessed immunohistochemically in 198 paraffin-embedded ovarian tissues and in an embryonal carcinoma model of cancer stemness. In parallel, expression of TLR4 and MyD88 mRNA and regulatory microRNAs (miR-21 and miR-146a) was assessed, as well as in a series of chemosensitive and resistant cancer cells lines. Functional analysis of the pathway was assessed in chemoresistant SKOV-3 ovarian cancer cells. TLR4 and MyD88 expression can be reproducibly assessed via immunohistochemistry using a semi-quantitative scoring system. TLR4 expression was present in all ovarian epithelium (normal and neoplastic), whereas MyD88 was restricted to neoplastic cells, independent of tumour grade and associated with reduced progression-free and overall survival, in an immunohistological specific subset of serous carcinomas, p<0.05. MiR-21 and miR-146a expression was significantly increased in MyD88 negative cancers (p<0.05), indicating their participation in regulation. Significant alterations in MyD88 mRNA expression were observed between chemosensitive and chemoresistant cells and tissue. Knockdown of TLR4 in SKOV-3 ovarian cells recovered chemosensitivity. Knockdown of MyD88 alone did not. MyD88 expression was down-regulated in differentiated embryonal carcinoma (NTera2) cells, supporting the MyD88+ cancer stem cell hypothesis. Our findings demonstrate that expression of MyD88 is associated with significantly reduced patient survival and altered microRNA levels and suggest an intact/functioning TLR4/MyD88 pathway is required for acquisition of the chemoresistant phenotype. Ex vivo manipulation of ovarian cancer stem cell (CSC) differentiation can decrease MyD88 expression, providing a potentially valuable CSC model for ovarian cancer