Differences In Kinematic Patterns Research Articles

Kinematic Sub-Populations in Bull Spermatozoa: A Comparison of Classical and Bayesian Approaches.

The ejaculate is heterogenous and sperm sub-populations with different kinematic patterns can be identified in various species. Nevertheless, although these sub-populations are statistically well defined, the statistical differences are not always relevant. The aim of the present study was to characterize kinematic sub-populations in sperm from two bovine species, and diluted with different commercial extenders, and to determine the statistical relevance of sub-populations through Bayesian analysis. Semen from 10 bulls was evaluated after thawing. An ISAS®v1 computer-assisted sperm analysis (CASA)-Mot system was employed with an image acquisition rate of 50 Hz and ISAS®D4C20 counting chambers. Sub-populations of motile spermatozoa were characterized using multivariate procedures such as principal components (PCs) analysis and clustering methods (k-means model). Four different sperm sub-populations were identified from three PCs that involved progressiveness, velocity, and cell undulatory movement. The proportions of the different sperm sub-populations varied with the extender used and in the two species. Despite a statistical difference (p < 0.05) between extenders, the Bayesian analysis confirmed that only one of them (Triladyl®) presented relevant differences in kinematic patterns when compared with Tris-EY and OptiXcell®. Extenders differed in the proportion of sperm cells in each of the kinematic sub-populations. Similar patterns were identified in Bos taurus and Bos indicus. Bayesian results indicate that sub-populations SP1, SP2, and SP3 were different for PC criteria and these differences were relevant. For velocity, linearity, and progressiveness, the SP4 did not show a relevant difference regarding the other sperm sub-populations. The classical approach of clustering or sperm subpopulation thus may not have a direct biological meaning. Therefore, the biological relevance of sperm sub-populations needs to be reevaluated.

Effect of taping on multi-segmental foot kinematic patterns during walking in persons with chronic ankle instability.

To evaluate multi-segmental foot kinematic patterns in chronic ankle instability (CAI) participants during walking, and to investigate the influence of high-Dye and low-Dye taping on these kinematic patterns. Cross-sectional study. Kinematic data of 12 non-injured controls and 15 CAI participants were measured with a three-dimensional motion analysis system during barefoot walking. In addition, the CAI participants walked with high-Dye and low-Dye taping. A rigid Plug-in gait model and the Rizzoli 3D Multi-Segment Foot Model were used to measure multi-segmental foot kinematic patterns. One-dimensional statistical parametric mapping was used to compare barefoot walking of the control and CAI group, and to evaluate differences between walking barefoot and walking with high-Dye and low-Dye taping within the CAI group. Compared to the control group, CAI participants showed a decreased ankle dorsiflexion during loading response (p=0.025) and a more inverted calcaneus in relation to the shank during the initial swing phase (p=0.024). A more inverted position of the metatarsus in relation to the midfoot was observed after low-Dye taping during almost the entire stance phase (p=0.017). No significant differences were found for high-Dye taping. Significant differences in kinematic patterns were found in the ankle joint and rearfoot, but not in the mid- and forefoot in CAI participants. The application of low-Dye taping resulted in a significantly increased inverted position of the forefoot, which can be considered as a less desirable effect for patients with CAI. No other effects of high-Dye and low-Dye taping on kinematic patterns were revealed.

Sprint cycling performance and asymmetry

The purpose of this study was to examine the asymmetries in cyclist’s lower limbs strength and in the pedalling kinematics during a seated sprinting test and to identify the relationships between asymmetries and maximal cycling power. 16 competitive road cyclists (20.6±3.7 yrs., 181.5±5.0 cm, 74.8±7.0 kg) performed 10 Sec isokinetic maximum power test with cadence 120 RPM. The asymmetry of kinematic patterns of cyclist’s upper and lower body during pedalling was registered. Separately isokinetic peak torque (PT) of main lover limbs joint were measured at angular speeds 60, 180 and 240⁰/s. The differences in kinematic patterns and isokinetic PT values between two limbs were analysed for descriptive and inferential statistics (relative share in %, correlations and regression between asymmetry values and cycling power). Conclusion: The highest asymmetries were found in cyclist’s upper body kinematics and at the same time the most symmetrical were knee extensors strength values, but both parameters were negatively and significantly correlated with the performance of sprint cycling. By combining the leg extensors muscular strength with asymmetry of knee extensors strength and trunk kinematics the explanatory power of multiple regressions increased markedly from 0.68 to 0.92.

Kinematics of ribbon‐fin locomotion in the bowfin, Amia calva

An elongated dorsal and/or anal ribbon-fin to produce forward and backward propulsion has independently evolved in several groups of fishes. In these fishes, fin ray movements along the fin generate a series of waves that drive propulsion. There are no published data on the use of the dorsal ribbon-fin in the basal freshwater bowfin, Amia calva. In this study, frequency, amplitude, wavelength, and wave speed along the fin were measured in Amia swimming at different speeds (up to 1.0 body length/sec) to understand how the ribbon-fin generates propulsion. These wave properties were analyzed to (1) determine whether regional specialization occurs along the ribbon-fin, and (2) to reveal how the undulatory waves are used to control swimming speed. Wave properties were also compared between swimming with sole use of the ribbon-fin, and swimming with simultaneous use of the ribbon and pectoral fins. Statistical analysis of ribbon-fin kinematics revealed no differences in kinematic patterns along the ribbon-fin, and that forward propulsive speed in Amia is controlled by the frequency of the wave in the ribbon-fin, irrespective of the contribution of the pectoral fin. This study is the first kinematic analysis of the ribbon-fin in a basal fish and the model species for Amiiform locomotion, providing a basis for understanding ribbon-fin locomotion among a broad range of teleosts.

KINEMATIC TRAJECTORIES WHILE WALKING WITHIN THE LOKOMAT ROBOTIC GAIT-ORTHOSIS

Purpose/Hypothesis: To compare the kinematic patterns of subjects walking in the Lokomat robotic gait-orthosis with those demonstrated during treadmill walking, and to quantify the amount of relative movement inside the device. The field of neurorehabilitation has been adopting robotic devices to help deliver mass-practice therapy to individuals with various types of neurological disorders (Hidler et al, 2005 for review). The Lokomat (Hocoma AG, Volketswil Switzerland) is the most widely adopted robotic system used for gait training. Previous studies have quantified changes in muscle activation pattern when subjects walk in the Lokomat to those on a treadmill (Hidler and Wall, 2005). No studies to date have tracked the kinematic patterns of the legs inside the Lokomat. Number of Subjects: 6 healthy subjects (4 male, 2 female) participated in the study. Materials/Methods: A Codamotion (Charnwood Dynamics, UK) motion analysis system was used to track the kinematic patterns of the subject's pelvis and legs, and the robotic limbs of the Lokomat. Marker clusters were placed on each limb segment and tracked at 100 Hz. Subjects walked on the treadmill with and without the Lokomat at four randomly selected walking speeds (2.0, 2.4, 2.8, 3.2 km/hr). For all trials, subject and Lokomat marker positions and ground reaction forces were recorded for 30-second step sequences. A number of kinematic metrics were compared between the two modalities using a one sample t-test (alpha = 0.05), including ankle, knee, and hip range of motion, maximum and minimum joint flexion and extension angles, and the point in the gait cycle each occurred. The relative knee and hip movement between the subject's and Lokomat's joint centers in both the frontal and sagittal planes were quantified. Results: While some subjects experienced slight differences in kinematic patterns, there were no significant differences in any of the metrics computed for all subjects across walking modalities. Despite there being no differences in sagittal joint angular patterns, the side to side motion of the hip in the medial-lateral plane was significantly less in the Lokomat than on the treadmill, sometimes restricted by as much as 75%. The relative movement of subjects' legs inside the Lokomat was substantial, where the variability in the knee joint center in the sagittal plane was approximately 1 cm while deviations exceeded 2 cm for the hip joint. Conclusions: With proper setup, the Lokomat gait patterns mimic those utilized during treadmill ambulation. Differences in the amount of medial-lateral hip motion can be attributed to the reduced degrees of freedom the Lokomat places on the subject. Clinical Relevance: The finding that there is significant movement of the subject's legs inside the Lokomat is important clinically, as a variable step pattern has been shown to be a more effective gait training strategy than one which forces the same kinematic pattern across successive steps (Cai et al., 2005).

Distribution of power across the hind limb joints in Labrador Retrievers and Greyhounds

To quantify angular excursions; net joint moments; and powers across the stifle, tarsal, and metatarsophalangeal (MTP) joints in Labrador Retrievers and Greyhounds and investigate differences in joint mechanics between these 2 breeds of dogs. 12 clinically normal dogs (6 Greyhounds and 6 Labrador Retrievers) with no history of hind limb lameness. Small retroreflective markers were applied to the skin over the pelvic limb joints, and a 4-camera kinematic system captured data at 200 Hz in tandem with force platform data while the dogs trotted on a runway. Breed-specific morphometric data were combined with kinematic and force data in an inverse-dynamics solution for stance-phase net joint moments and powers at the stifle, tarsal, and MTP joints. There were gross differences in kinematic patterns between Greyhounds and Labradors. At the stifle and tarsal joints, moment and power patterns were similar in shape, but amplitudes were larger for the Greyhounds. The MTP joint was a net absorber of energy, and this was greater in the Greyhounds. Greyhounds had a positive phase across the stifle, tarsal, and MTP joints at the end of stance for an active push-off, whereas for the Labrador Retrievers, the only positive phase was across the tarsus, and this was small, compared with values for the Greyhounds. Gross differences in pelvic limb mechanics are evident between Greyhounds and Labrador Retrievers. Joint kinetics in specific dogs should be compared against breed-specific patterns.

Intra-stride belt-speed variation affects treadmill locomotion.

For overground and treadmill locomotion to be mechanically similar, it is required that the belt speed of the treadmill is constant and the same to that of overground locomotion. Variation of the belt speed during a stride causes exchange of energy between the subject and the treadmill. This might be the cause of different kinematic patterns between overground and treadmill locomotion, which have been reported in literature. The aim of this study was to investigate whether the intra-stride belt-speed is variable, and whether differences in kinematic patterns can be attributed to these variations. Nine subjects walked and ran overground and on two treadmills that were differently susceptible to subjects' braking and accelerating forces. It was found that the speed variations during treadmill locomotion affect the kinematic parameters significantly. The amount of intra-stride belt-speed variation was found to depend on the power of the treadmill and the mass of the subject. Copyright 1998 Elsevier Science B.V.

Kinematics of Aquatic Prey Capture in the Snapping Turtle Chelydra Serpentina

ABSTRACT The kinematics of feeding on two prey types is studied quantitatively in the common snapping turtle, Chelydra serpentina, to provide a description of prey capture mechanisms and to determine whether kinematic patterns can be altered in response to prey that vary in escape capability. High-speed video recordings of prey capture (200 fields s-1) provide data for field-by-field analysis of 12 kinematic variables characterizing head and neck movement. Feedings on fish were accomplished in 78 ms, with peak head extension velocities of 152.5 cm s-1. Worm feedings lasted 98 ms with maximum head extension velocities of 54cms-1. Both univariate and multivariate statistical analyses demonstrate significant differences in kinematic patterns between fish and earthworm feedings: Chelydra serpentina possesses the ability to modulate its kinematic pattern depending on the prey. The pattern of bone movement during the fast opening phase of the gape cycle is similar to that found in ray-finned fishes, lungfishes and aquatic salamanders. However, movements of the cranium and lower jaw during the closing phase are markedly different. Our data show Chelydra to be predominantly a ram-feeder, with any intraoral negative pressures generated during the strike having a negligible effect on the prey, which remains largely stationary relative to a fixed background. Hyoid and esophageal expansion during the closing phase may function to allow a unidirectional flow of water and prey into the mouth until the gape closes and to delay reverse flow until the prey has been trapped inside the mouth. The independent evolutionary acquisition of aquatic feeding in fishes and turtles reveals some kinematic similarities that may be the result of hydrodynamic constraints on aquatic prey capture systems, as well as kinematic differences that result from the fundamentally different morphological design of the prey capture apparatus.