Factors influencing the response to therapy in dogs with eosinophilic bronchopneumopathy.

OBJECTIVES: Canine eosinophilic bronchopneumopathy (EBP) is a poorly understood disease characterized by chronic inflammation of the lower airways. To date, factors affecting the course of the disease are largely unknown. The objective of this study was to investigate the influence of clinical, laboratory, and environmental factors on therapeutic outcome in dogs with EBP. MATERIAL AND METHODS: Environmental and housing conditions, course of disease, and response to treatment were evaluated using a standardized questionnaire for owners of 29 dogs diagnosed with EBP from 3 different veterinary referral centers in Germany. Data of diagnostic tests (hematology, radiographs, bronchoalveolar-lavage-fluid-(BALF) cytology) were retrospectively obtained from medical records. The influence of the different factors was assessed using Fisher's-exact-test and Mann-Whitney-U- or Kruskal-Wallis-test. RESULTS: The proportion of neutrophilic granulocytes in BALF-cytology was significantly higher in dogs with persistent clinical signs compared to dogs that achieved clinical remission (p=0.029). Duration of clinical signs before treatment was significantly longer in dogs with persistent clinical signs (16±12 months) compared to dogs that achieved clinical remission (6±7 months) (p=0.017). CONCLUSION: Early diagnosis and therapy have a decisive influence on the success of treatment. CLINICAL RELEVANCE: Dogs with respiratory signs suspicious for EBP should be evaluated in a timely manner to increase the likelihood of clinical remission with an early start of therapy.

Comparison of a Pure Plug-Based Versus a Primary Suture-Based Vascular Closure Device Strategy for Transfemoral Transcatheter Aortic Valve Replacement: The CHOICE-CLOSURE Randomized Clinical Trial.

BACKGROUND: Transcatheter aortic valve replacement is an established treatment option for patients with severe symptomatic aortic stenosis and is most commonly performed through the transfemoral access route. Percutaneous access site closure can be achieved using dedicated plug-based or suture-based vascular closure device (VCD) strategies, but randomized comparative studies are scarce. METHODS: The CHOICE-CLOSURE trial (Randomized Comparison of Catheter-based Strategies for Interventional Access Site Closure during Transfemoral Transcatheter Aortic Valve Implantation) is an investigator-initiated, multicenter study, in which patients undergoing transfemoral transcatheter aortic valve replacement were randomly assigned to vascular access site closure using either a pure plug-based technique (MANTA, Teleflex) with no additional VCDs or a primary suture-based technique (ProGlide, Abbott Vascular) potentially complemented by a small plug. The primary end point consisted of access site- or access-related major and minor vascular complications during index hospitalization, defined according to the Valve Academic Research Consortium-2 criteria. Secondary end points included the rate of access site- or access-related bleeding, VCD failure, and time to hemostasis. RESULTS: A total of 516 patients were included and randomly assigned. The mean age of the study population was 80.5±6.1 years, 55.4% were male, 7.6% of patients had peripheral vascular disease, and the mean Society of Thoracic Surgeons score was 4.1±2.9%. The primary end point occurred in 19.4% (50/258) of the pure plug-based group and 12.0% (31/258) of the primary suture-based group (relative risk, 1.61 [95% CI, 1.07-2.44], P=0.029). Access site- or access-related bleeding occurred in 11.6% versus 7.4% (relative risk, 1.58 [95%CI: 0.91-2.73], P=0.133) and device failure in 4.7% versus 5.4% (relative risk, 0.86, [95% CI, 0.40-1.82], P=0.841) in the respective groups. Time to hemostasis was significantly shorter in the pure plug-based group (80 [32-180] versus 240 [174-316] seconds, P<0.001). CONCLUSIONS: Among patients treated with transfemoral transcatheter aortic valve replacement, a pure plug-based vascular closure technique using the MANTA VCD is associated with a higher rate of access site- or access-related vascular complications but a shorter time to hemostasis compared with a primary suture-based technique using the ProGlide VCD. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT04459208.

Clinical relevance of intradermal test results in atopic dogs.

TOPIC AND AIMS: Canine atopic dermatitis (AD) is an inflammatory and pruritic skin disease and in most cases associated with IgE antibodies against environmental allergens. To date, the only causative therapeutic option is allergen immunotherapy (AIT). Offending allergens for AIT can be identified by intradermal testing (IDT) or serum allergen-specific IgE testing. The aim of the study was to evaluate positive IDT results considering the atopic dogs' clinical history. MATERIAL AND METHODS: An IDT was performed on 48 atopic dogs and their owners completed a detailed questionnaire about the seasonal course of their pruritus. Results of IDT were correlated with the seasonal occurrence of pruritus. RESULTS: The most common positive IDT reactions were observed to mite allergens (33.3-62.5 %). Prevalence of positive reactions to individual tree, grass and weed pollen ranged between 8.3 % and 25 %. Moulds and epithelial allergens produced positive reactions in only 0-6.3 %. A correlation between positive IDT reactions and course of pruritus could neither be found for perennial nor for seasonal allergens. CONCLUSION: The evaluation of IDT reactions may not be an optimal method for identification of clinically relevant allergens in canine AD. CLINICAL RELEVANCE: The results of this study emphasise the importance of considering clinical history in addition to allergy test results in the formulation of an allergen extract for desensitisation.

Sample preparation for analytical scanning electron microscopy using initial notch sectioning.

A novel method for broad ion beam based sample sectioning using the concept of initial notches is presented. An adapted sample geometry is utilized in order to create terraces with a well-define d step in erosion depth from the surface. The method consists of milling a notch into the surface, followed by glancing-angle ion beam erosion, which leads to preferential erosion at the notch due to increased local surface elevation. The process of terrace formation can be utilized in sample preparation for analytical scanning electron microscopy in order to get efficient access to the depth-dependent microstructure of a material. It is demonstrated that the method can be applied to both conducting and non-conducting specimens. Furthermore, experimental parameters influencing the preparation success are determined. Finally, as a proof-of-concept, an electron backscatter diffraction study on a surface crystallized diopside glass ceramic is performed, where the method is used to analyze orientation dependent crystal growth phenomena occurring during growth of surface crystals into the bulk.

Molecular Dynamics Study of Wetting and Adsorption of Binary Mixtures of the Lennard-Jones Truncated and Shifted Fluid on a Planar Wall.

The wetting of surfaces is strongly influenced by adsorbate layers. Therefore, in this work, sessile drops and their interaction with adsorbate layers on surfaces were investigated by molecular dynamics simulations. Binary fluid model mixtures were considered. The two components of the fluid mixture have the same pure component parameters, but one component has a stronger and the other a weaker affinity to the surface. Furthermore, the unlike interactions between both components were varied. All interactions were described by the Lennard-Jones truncated and shifted potential with a cutoff radius of 2.5σ. The simulations were carried out at constant temperature for mixtures of different compositions. The parameters were varied systematically and chosen such that cases with partial wetting as well as cases with total wetting were obtained and the relation between the varied molecular parameters and the phenomenological behavior was elucidated. Data on the contact angle as well as on the mole fraction and thickness of the adsorbate layer were obtained, accompanied by information on liquid and gaseous bulk phases and the corresponding phase equilibrium. Also, the influence of the adsorbate layer on the wetting was studied: for a sufficiently thick adsorbate layer, the wall's influence on the wetting vanishes, which is then only determined by the adsorbate layer.

Soft Interference Cancellation for Random Coding in Massive Gaussian Multiple-Access.

In 2017, Polyanskiy showed that the trade-off between power and bandwidth efficiency for massive Gaussian random access is governed by two fundamentally different regimes: low power and high power. For both regimes, tight performance bounds were found by Zadik et al., in 2019. This work utilizes recent results on the exact block error probability of Gaussian random codes in additive white Gaussian noise to propose practical methods based on iterative soft decoding to closely approach these bounds. In the low power regime, this work finds that orthogonal random codes can be applied directly. In the high power regime, a more sophisticated effort is needed. This work shows that power-profile optimization by means of linear programming, as pioneered by Caire et al. in 2001, is a promising strategy to apply. The proposed combination of orthogonal random coding and iterative soft decoding even outperforms the existence bounds of Zadik et al. in the low power regime and is very close to the non-existence bounds for message lengths around 100 and above. Finally, the approach of power optimization by linear programming proposed for the high power regime is found to benefit from power imbalances due to fading which makes it even more attractive for typical mobile radio channels.

Groin Injuries in Soccer: Investigating the Effect of Age on Adductor Muscle Forces.

PURPOSE: The sudden rise in the injury incidence during adolescence is also evident in soccer-related injuries to the groin. Submaximal passing applies high stress on the adductor muscles and pubic symphysis and is therefore likely to be connected to the occurrence of groin injuries. Therefore, the purpose of the study was to compare hip joint kinematics and adductor muscle forces of different adolescent age groups during submaximal soccer passing. METHODS: Sixty participants, in four groups, younger than 12, 15, 16. and 23 yr (U12, U15, U16, U23), were analyzed. A Footbonaut, equipped with a 3D motion capture system consisting of 16 cameras, was used to capture kinematic data of short passes. Inverse dynamic analysis was performed to calculate muscle forces of 10 passes of each subject. RESULTS: The U15 group showed reduced angular velocities. A rise in hip adductor muscle forces was evident from the youngest group up to the oldest groups. The largest increase (49%) was found between U12 and U15. Lower-limb mass was identified as the best predictor for the increasing adductor force. CONCLUSIONS: The reduced angular velocities of the U15 and the increase in muscle forces between all age groups were attributed to the increasing segment masses and length. This increases the moments of inertia of the leg segments thereby demanding higher forces to accelerate the segments. Most likely, the stress put upon the adductors apophyses increases during adolescence, as tendons are known to adapt slower than muscles, increasing the risk for overuse injuries. Coaches could use lower-limb mass as an indicator for fast increases in the force demand to identify players who would benefit from a reduced training volume.

Functional implications of Cav 2.3 R-type voltage-gated calcium channels in the murine auditory system - novel vistas from brainstem-evoked response audiometry.

Voltage-gated Ca2+ channels (VGCCs) are considered to play a key role in auditory perception and information processing within the murine inner ear and brainstem. In the past, Cav 1.3 L-type VGCCs gathered most attention as their ablation causes congenital deafness. However, isolated patch-clamp investigation and localization studies repetitively suggested that Cav 2.3 R-type VGCCs are also expressed in the cochlea and further components of the ascending auditory tract, pointing to a potential functional role of Cav 2.3 in hearing physiology. Thus, we performed auditory profiling of Cav 2.3+/+ controls, heterozygous Cav 2.3+/- mice and Cav 2.3 null mutants (Cav 2.3-/- ) using brainstem-evoked response audiometry. Interestingly, click-evoked auditory brainstem responses (ABRs) revealed increased hearing thresholds in Cav 2.3+/- mice from both genders, whereas no alterations were observed in Cav 2.3-/- mice. Similar observations were made for tone burst-related ABRs in both genders. However, Cav 2.3 ablation seemed to prevent mutant mice from total hearing loss particularly in the higher frequency range (36-42 kHz). Amplitude growth function analysis revealed, i.a., significant reduction in ABR wave WI and WIII amplitude in mutant animals. In addition, alterations in WI -WIV interwave interval were observed in female Cav 2.3+/- mice whereas absolute latencies remained unchanged. In summary, our results demonstrate that Cav 2.3 VGCCs are mandatory for physiological auditory information processing in the ascending auditory tract.

Long jumpers with and without a transtibial amputation have different three-dimensional centre of mass and joint take-off step kinematics.

Long jumpers with below the knee amputation (BKA) have achieved remarkable performances, yet the underlying biomechanics resulting in these jump distances are unknown. We measured three-dimensional motion and used multi-segment modelling to quantify and compare the centre of mass (COM) and joint kinematics of three long jumpers with BKA and seven non-amputee long jumpers during the take-off step of the long jump. Despite having the same jump distances, athletes with BKA, who used their affected leg for the take-off step, had lower sagittal plane hip and knee joint range of motion and positioned their affected leg more laterally relative to the COM compared to non-amputee athletes. Athletes with BKA had a longer compression phase and greater downward movement of their COM, suggesting that their affected leg (lever) was less rigid compared to the biological leg of non-amputees. Thus, athletes with BKA used a different kinematic mechanism to redirect horizontal to vertical velocity compared to non-amputee athletes. The specific movement patterns of athletes with BKA during the take-off step were constrained by the mechanical properties of the prosthesis. These results provide a basis for coaches and athletes to develop training protocols that improve performance and inform the design of future prostheses.

Data Acquisition and Analysis In Brainstem Evoked Response Audiometry In Mice.

Brainstem evoked response audiometry (BERA) is of central relevance in the clinical neurophysiology. As other evoked potential (EP) techniques, such as visually evoked potentials (VEPs) or somatosensory evoked potentials (SEPs), the auditory evoked potentials (AEPs) are triggered by the repetitive presentation of identical stimuli, the electroencephalographic (EEG) response of which is subsequently averaged resulting in distinct positive (p) and negative (n) deflections. In humans, both the amplitude and the latency of individual peaks can be used to characterize alterations in synchronization and conduction velocity in the underlying neuronal circuitries. Importantly, AEPs are also applied in basic and preclinical science to identify and characterize the auditory function in pharmacological and genetic animal models. Even more, animal models in combination with pharmacological testing are utilized to investigate for potential benefits in the treatment of sensorineural hearing loss (e.g., age- or noise-induced hearing deficits). Here we provide a detailed and integrative description of how to record auditory brainstem-evoked responses (ABRs) in mice using click and tone-burst application. A specific focus of this protocol is on pre-experimental animal housing, anesthesia, ABR recording, ABR filtering processes, automated wavelet-based amplitude growth function analysis, and latency detection.

Cav3.2 T-Type Calcium Channels Are Physiologically Mandatory for the Auditory System.

Voltage-gated Ca2+ channels (VGCCs) play key roles in auditory perception and information processing within the inner ear and brainstem. Pharmacological inhibition of low voltage-activated (LVA) T-type Ca2+ channels is related to both age- and noise induced hearing loss in experimental animals and may represent a promising approach to the treatment of auditory impairment of various etiologies. Within the LVA Ca2+ channel subgroup, Cav3.2 is the most prominently expressed T-type channel entity in the cochlea and auditory brainstem. Thus, we performed a complete gender specific click and tone burst based auditory brainstem response (ABR) analysis of Cav3.2+/- and Cav3.2-/- mice, including i.a. temporal progression in hearing loss, amplitude growth function and wave latency analysis as well as a cochlear qPCR based evaluation of other VGCCs transcripts. Our results, based on a self-programmed automated wavelet approach, demonstrate that both heterozygous and Cav3.2 null mutant mice exhibit age-dependent increases in hearing thresholds at 5 months of age. In addition, complex alterations in WI-IV amplitudes and latencies were detected that were not attributable to alterations in the expression of other VGCCs in the auditory tract. Our results clearly demonstrate the important physiological role of Cav3.2 VGCCs in the spatiotemporal organization of auditory processing in young adult mice and suggest potential pharmacological targets for interventions in the future.

Gender specific click and tone burst evoked ABR datasets from mice lacking the Cav3.2 T-type voltage-gated calcium channel.

OBJECTIVES: Voltage-gated Ca2+ channels (VGCCs) are of central relevance in regulating Ca2+ influx into living cells. The low-voltage activated (LVA) Cav3 T-type Ca2+ channels are widely distributed throughout the brain including the peripheral auditory system and ascending auditory tract. Their exact role in auditory information processing is still not fully understood. Within the LVA subgroup, Cav3.2 T-type Ca2+ channels seem to be of special importance as qPCR revealed a steady increase in Cav3.2 transcript levels over age, e.g. in the cochlea and spiral ganglion neurons (SGN). Furthermore, pharmacological studies suggested an association between Cav3.2 expression and both age-related and noise-induced hearing loss. Given the potential functional relevance of Cav3.2 VGGCs in sensorineural hearing loss, we recorded gender specific auditory evoked brainstem responses (ABRs) upon both click and tone burst presentation. Here we present auditory brainstem response (ABR) data from Cav3.2+/+, Cav3.2+/- and Cav3.2-/- mice from both genders which are of value for researchers who want to evaluate how Cav3.2 loss affects basic auditory parameters, e.g. click and tone burst based hearing thresholds, amplitude growth function and peak latencies. DATA DESCRIPTION: Information presented here includes ABR data from age-matched female and male Cav3.2+/+, Cav3.2+/- and Cav3.2-/- mice and technical aspects of the auditory recording protocol. Data were recorded using a commercially available ABR setup from Tucker Davis Technologies Inc. (TDT). Raw data files (arf.-file format) were exported as txt.-files with free access for analysis.

Vertical stiffness during one-legged hopping with and without using a running-specific prosthesis.

Although athletes with unilateral below-the-knee amputations (BKAs) generally use their affected leg, including their prosthesis, as their take-off leg for the long jump, little is known about the spring-like leg behavior and stiffness regulation of the affected leg. The purpose of this study was to investigate vertical stiffness during one-legged hopping in an elite-level long jump athlete with a unilateral BKA. We used the spring-mass model to calculate vertical stiffness, which equals the ratio of maximum vertical ground reaction force to maximum center of mass displacement, while the athlete with a BKA hopped on one leg at a range of frequencies. Then, we compared the vertical stiffness of this athlete to seven non-amputee elite-level long-jumpers. We found that from 1.8 to 3.4 Hz, the vertical stiffness of the unaffected leg for an athlete with a BKA increases with faster hopping frequencies, but the vertical stiffness of the affected leg remains nearly constant across frequencies. The athlete with a BKA attained the desired hopping frequencies at 2.2 and 2.6 Hz, but was unable to match the lowest (1.8 Hz) and two highest frequencies (3.0 and 3.4 Hz) using his affected leg. We also found that at 2.5 Hz, unaffected leg vertical stiffness was 15% greater than affected leg vertical stiffness, and the vertical stiffness of non-amputee long-jumpers was 32% greater than the affected leg vertical stiffness of an athlete with a BKA. The results of the present study suggest that the vertical stiffness regulation strategy of an athlete with a unilateral BKA is not the same in the unaffected versus affected legs, and compared to non-amputees.

Leg amputation side determines performance in curve sprinting: a case study on a Paralympic medalist.

The lower limb kinetics of curve sprinting in amputees are not well described in the literature, particularly with respect to the effect of the side of amputation. This is an issue due to the importance of the knowledge for prosthetic design and classification of athletes. Thus, the aim of this study was to investigate the influence of side of amputation on curve sprinting performance in athletes with a unilateral leg amputation. A three-dimensional motion analysis system (Vicon), four force plates (Kistler) and a modified mathematical human model (ALASKA) were used to compare clockwise and counter clockwise curve sprinting lower limb kinematics and kinetics of a Paralympic medalist with a left-sided knee exarticular amputation. Results reveal that vertical ground reaction force application and total vertical impulse were lower when the affected limb was at the inside of the curve. The unaffected limb showed joint mechanics different to those established for non-amputee athletes and might contribute better to propulsion when being the inside limb. Curve sprinting biomechanics and the ability to attain high radial velocities are directly dependent on the side of amputation relative to the curve direction in a unilateral amputee athlete of highest performance level.

Spatiotemporal parameters in sprinters with unilateral and bilateral transfemoral amputations and functional impairments.

PURPOSE: Although sprinters with unilateral (UTF) and bilateral transfemoral (BTF) amputations and functional impairments (FIs) without amputation were allocated into different classifications because of the recent revision of the International Paralympic Committee Athletics Rules and Regulations, it is unclear whether running mechanics differ among the three groups. The aim of this study was to investigate the differences in the spatiotemporal parameters of the three groups during 100-m sprint in official competitions. METHODS: Using publicly available Internet broadcasts, we analyzed 11 elite-level sprinters with UTF amputation, 4 sprinters with BTF amputation, and 5 sprinters with FI without amputation. The best personal times for nearly all individuals were included. For each sprinter's race, the average speed, step frequency, and step length were calculated using the number of steps in conjunction with the official race time. RESULTS: Although there were no significant differences in the average speed among the UTF, BTF, and FI groups (7.95 ± 0.22, 7.90 ± 0.42, and 7.93 ± 0.14 m/s, respectively, p = 0.87), those with BTF amputation showed significantly lower step frequency (UTF: 4.20 ± 0.20 Hz, BTF: 3.71 ± 0.32 Hz, FI: 4.20 ± 0.10 Hz, p < 0.05) and longer step length (UTF: 1.90 ± 0.08 m, BTF: 2.14 ± 0.02 m, FI: 1.89 ± 0.06 m, p < 0.05) than the other two groups. CONCLUSION: These results suggest that the step characteristics during sprinting are not the same among sprinters with UTF amputation, BTF amputations, or FI without amputations.

Three-Dimensional Takeoff Step Kinetics of Long Jumpers with and without a Transtibial Amputation.

PURPOSE: The loads applied on the musculoskeletal system during the long jump takeoff step are not well established for nonamputee athletes or athletes with a lower extremity amputation. Information on joint loading and potential injury mechanisms is important for improving training or rehabilitation protocols, prosthetic design, and the general understanding of the long jump. METHODS: Three-dimensional takeoff step kinematics and kinetics were used for inverse dynamic model calculations on three male athletes with and seven male athletes without a below the knee amputation (BKA). Athletes with BKA used their affected leg as their takeoff leg. RESULTS: Despite equivalent long jump performance, ground reaction force application characteristics were widely different, and calculated joint loads were significantly lower in athletes with BKA compared with nonamputee athletes during the takeoff step. The takeoff step of the long jump for athletes with BKA seems to be dominated by sagittal plane movements, whereas it involves sagittal plane movement and compensatory joint work in the frontal plane for nonamputee athletes. CONCLUSIONS: Coaches and athletes should adapt training protocols to the unique musculoskeletal loading patterns of long jumpers with or without a BKA. Specifically, nonamputee athletes should strengthen the muscles responsible for hip and knee extension, as well as for frontal plane stabilization, early in the season to avoid injuries. The presented data enable clinicians to identify potential causes of pain or injury more differentially in both groups of athletes and might stimulate future research in the field of robotics and prosthetic components. Furthermore, the altered joint mechanics of athletes with BKA versus nonamputees serves as an explanation for their previously described more effective takeoff step.

Gender specific click and tone burst evoked ABR datasets from mice lacking the Cav2.3 R-type voltage-gated calcium channel.

This data article provides raw auditory evoked brainstem responses (ABRs) from controls and Cav2.3 transgenics, i.e. heterozygous Cav2.3+/- and Cav2.3-/- null mutants. Gender specific ABR recordings were performed in age-matched animals under ketamine/xylazine narcosis. Data presented here include ABRs upon both click and tone burst presentation in the increasing SPL mode using a commercially available ABR setup from Tucker Davis Technologies Inc. (TDT, USA). Detailed information is provided for the sound attenuating cubicle, electrical shielding, electrode parameters, stimulus characteristics and architecture, sampling rate, filtering processes and ABR protocol application during the course of data acquisition and recording. The later are important for subsequent analysis of click and tone burst related hearing thresholds, amplitude growth function and peak latencies. Raw data are available at MENDELEY DATA, DIO: 〈DOI:10.17632/g6ygz2spzx.1〉, URL: 〈https://data.mendeley.com/datasets/g6ygz2spzx/1〉).

Three-dimensional phase field modeling of inhomogeneous gas-liquid systems using the PeTS equation of state.

Recently, an equation of state (EoS) for the Lennard-Jones truncated and shifted (LJTS) fluid has become available. As it describes metastable and unstable states well, it is suited for predicting density profiles in vapor-liquid interfaces in combination with density gradient theory (DGT). DGT is usually applied to describe interfaces in Cartesian one-dimensional scenarios. In the present work, the perturbed LJ truncated and shifted (PeTS) EoS is implemented into a three-dimensional phase field (PF) model which can be used for studying inhomogeneous gas-liquid systems in a more general way. The results are compared with the results from molecular dynamics simulations for the LJTS fluid that are carried out in the present work and good agreement is observed. The PF model can therefore be used to overcome the scale limit of molecular simulations. A finite element approach is applied for the implementation of the PF model. This requires the first and second derivatives of the PeTS EoS which are calculated using hyper-dual numbers. Several tests and examples of applications of the new PeTS PF model are discussed.

Does inside passing contribute to the high incidence of groin injuries in soccer? A biomechanical analysis.

Groin injuries are common in soccer and often cause time-loss from training. While groin injuries have been linked to full effort kicking, the role of inside passing is unclear. Therefore, the purpose of this study was to investigate hip joint kinematics and muscle force, stress and contraction velocity for adductor longus and gracilis during inside passing. 3D kinematics of ten soccer players (23.4 yrs; 77.5 kg; 1.81 m) were captured with a motion capture system inside a Footbonaut. Muscle force and contraction velocity were determined with AnyBody Modelling System. Gracilis muscle forces were 9% lower compared to adductor longus (p = 0.005), but muscle stress was 183% higher in gracilis (p = 0.005). Contraction velocity reveals eccentric contraction of gracilis in the last quarter of the swing phase. Considering the combination of eccentric contraction, high muscle stress and the repetitive nature of inside passing, gracilis accumulates high loads in matches and training. These results indicate that the high incidence of groin injuries in soccer could be linked to isolated pass training. Practitioners need to be aware of the risk and refrain from sudden increases in the amount of pass training. This gives the musculoskeletal system time to adapt and might avoid career threatening injuries.

First and Second Step Characteristics of Amputee and Able-Bodied Sprinters.

CONTEXT: In sprint events, the first 2 steps are used to accelerate the center of mass horizontally and vertically. Amputee athletes cannot actively generate energy with their running-specific prosthesis. It is likely that sprint acceleration mechanics, including step asymmetry, are altered compared with able-bodied athletes. PURPOSE: To investigate spatiotemporal and kinetic variables of amputee compared with able-bodied sprinters. METHODS: Kinematic and kinetic data of the first and second stance were collected from 15 able-bodied and 7 amputee sprinters (2 unilateral transfemoral, 4 unilateral transtibial, and 1 bilateral transtibial) with a motion-capture system (250 Hz) and 2 force plates (1000 Hz). In addition, bilateral asymmetry was quantified and compared between groups. RESULTS: Compared with able-bodied athletes, amputee athletes demonstrated significantly lower performance values for 5- and 10-m times. Step length, step velocity, and step frequency were decreased and contact times increased. Peak horizontal force and relative change of horizontal velocity were decreased in both stances. Peak vertical force and relative change of vertical velocity were lower for the amputee than the able-bodied group during the first stance but significantly higher during the second stance. During the first stance, able-bodied and amputee sprinters displayed a similar orientation of the ground-reaction-force vector, which became more vertically orientated in the amputee group during second stance. Amputee sprinters showed significantly greater asymmetry magnitudes for vertical force kinetics compared with able-bodietd athletes. CONCLUSION: A running-specific prosthesis does not replicate the function of the biological limb well in the early acceleration phase.