Sagittal plane inclination of the trunk and tibia have been shown to independently modulate hip and knee extensor moments during squatting. The purpose of this study was to determine if the ...difference between sagittal plane trunk and tibia inclinations can be used to approximate the relative demand of the hip and knee extensors across a range of squatting conditions. Kinematic and kinetic data were obtained from 16 participants during 8 squat conditions in which trunk and tibia inclination were manipulated. The average hip/knee extensor moment ratio (HKR) was calculated during the lowering (eccentric) phase of each squat condition using inverse dynamics equations. Linear regression evaluated the association between the difference in trunk and tibia inclination at peak knee flexion and the average HKR. Across all squat conditions, the difference between trunk and tibia inclinations explained 70% of the variance in the average HKR (p < 0.001). The squat was knee extensor biased (HKR ≤ 1.0) when the tibia was at least 8 degrees more inclined than the trunk. The results of this study indicate that the relationship between sagittal plane trunk and tibia inclination can be used to estimate the relative demand of the hip and knee extensors.
Radiographic evaluation in adult spinal deformity (ASD) offers no information on spinopelvic alignment and compensation during dynamic conditions. Motion analysis offers the potential to bridge the ...gap between static radiographic and dynamic alignment measurement, increasing our understanding on how ASD impacts function.
This study aimed to explore the changes in sagittal alignment and compensation strategies in ASD between upright standing and walking, compared to control subjects and within different sagittal alignment groups. Ten patients were measured pre- and six months postoperatively to explore the impact of surgical alignment correction on gait.
Prospective study.
Full protocol: 58 ASD and 20 controls; Spinal kinematic analysis: 43 ASD and 18 controls; Postoperative analysis: 10 ASD.
Standing and walking sagittal spinopelvic (thoracic kyphosis (TK), lumbar lordosis (LL), sagittal vertical axis (SVA), pelvis), and lower limb kinematics, spinopelvic changes between standing and walking (∆ ie, difference between mean dynamic and static angle), lower limb kinetics, spatiotemporal parameters, balance (BESTest), patient-reported outcome scores (SRS-22r, ODI, and FES-I) and radiographic parameters.
Motion analysis was used to assess the standing and walking spinopelvic and lower limb kinematics, as well as the lower limb kinetics during walking. All parameters were compared between controls and patients with ASD, divided in three groups based on their sagittal alignment (ASD 1: decompensated sagittal malalignment; ASD 2: compensated sagittal malalignment; ASD 3: scoliosis and normal sagittal alignment). Ten patients were reassessed 6 months after spinal corrective surgery. Continuous kinematic and kinetic data were analyzed through statistical parametric mapping.
All patient groups walked with increased forward trunk tilt (∆SVA=41.43 mm, p<.001) in combination with anterior pelvic tilt (∆Pelvis=2.58°, p<.001) compared to standing, as was also observed in controls (∆SVA=37.86 mm, p<.001; ∆Pelvis=1.62°, p=.012). Patients walked with increased SVA, in combination with decreased LL and alterations in lower limb kinematics during terminal stance and initial swing, as well as altered spatiotemporal parameters. Subgroup analysis could link these alterations in gait to sagittal spinopelvic malalignment (ASD 1 and 2). After surgical correction, lower limb kinematics and spatiotemporal parameters during gait were not significantly improved.
To compensate for increased trunk tilt and pelvic anteversion during walking, patients with sagittal malalignment show altered lower limb gait patterns, which have previously been associated with increased risk of falling and secondary lower limb pathology. Since surgical correction of the deformity did not lead to gait improvements, further research on the underlying mechanisms is necessary to improve our understanding of how ASD impacts function.
Sensitivity analysis of the knee joint response to variations in gait kinematics-kinetics as reported in the literature is crucial for improved understanding and more effective prevention-treatment ...strategies. Using our validated finite element-musculoskeletal (FE-MS) model of lower extremity, we investigate the sensitivity of knee anterior cruciate ligament (ACL), muscle, and contact forces plus stability to the reported scatter in asymptomatic gait data. Three highly loaded stance instants (25, 50 and 75%) with five levels (mean, ±0.5SD and ±SD) for each of six knee joint angles-moments are used employing Taguchi approach (25 experiments) and regression equations. ACL force drops significantly at larger flexion angles (all periods) and smaller internal moment (at 75% only) but increases with the flexion moment. Tibiofemoral (TF) medial-lateral contact force partitioning is found, contrary to the common claim, most sensitive to changes in the adduction angle and not in the adduction moment. Total TF contact force increases significantly at greater moments (but not angles), especially in the sagittal plane. Forces in lateral hamstrings are significantly influenced by changes in adduction angles-moments. Larger flexion moments (at 25 and 50%) significantly increase forces in quadriceps and on patellofemoral (PF) contact. Sagittal moment, adduction moment (at 75%) and flexion angle (at 25%) contribute most to the joint stability. A strong inverse correlation exists between the joint stability and the total TF compression force. These findings can be exploited to adapt and modify intact, injured and reconstructed knee joint responses during gait.
This study aimed to (1) track changes in body composition, lower body force-time characteristics, and swim start performance over a competitive season, and (2) investigate the intra-individual ...associations between changes in body composition and lower body force-time characteristics to swim start performance in five high performance swimmers (three males, two females). Over a ∼12-month period, body composition, lower body force-time characteristics and swim start performance were assessed at three time points via DXA scan, squat jump and swim start performance test (start times to 5 and 15 m and several kinematic and kinetic outputs). Throughout a competitive season of concurrent swimming and dry-land resistance training, improvements in lower body lean mass and squat jump force-time characteristics were observed. However, changes in start times varied between athletes. Total body and lower body lean mass both displayed large negative correlations with the time spent in the entry and propulsive underwater phases (r = –0.57 to –0.66), along with a large positive correlations with glide time (r = 0.56–0.53). Additionally, lower body lean mass exhibited large to very large positive correlations with the flight phase (r = 0.70–0.73). Overall, these findings provide some insight into the potential magnitude of change in body composition, lower body force-time characteristics and swim start performance in high performance swimmers within a season. The large to very large correlations between increased lower body lean mass and SJ force-time metrics to improvements in aspects of start performance may provide useful information to coaches and sports scientists.
The effective utilisation of braking ground reaction forces is considered an essential biomechanical characteristic of fast bowling in cricket. The configuration of the trunk and legs during the ...delivery stride phase has been hypothesised to increase braking forces, causing the upper body segments to increase their angular momentum and thereby increase ball release speed. This study investigated the relationship between V-spine angle, front shank angle (plant angle) and front knee angle with braking ground reaction forces and ball release speed. Three-dimensional kinematic and kinetic analyses were performed for 17 male pace bowlers (17.2 ± 1.7 years) of New South Wales grade club level using data from a Cortex 2.0 motion analysis system (200 Hz) and Kistler force plates (1000 Hz). V-spine angle was strongly and significantly correlated with braking ground reaction force (r = −0.691), plant angle (r = −0.806) and front knee angle (r = −0.606). In addition, stepwise multiple linear regression analysis revealed that front shank angle was the strongest predictor of braking ground reaction force. The data suggests that V-spine angle and plant angle may play an important role in generating high braking ground reaction forces in bowling, with the front knee angle possibly playing a supporting role. Coaches may need to consider these findings when assessing the techniques of pace bowlers.
Golf putting requires accuracy and precision. However, environmental factors can influence the accuracy and stability of the putt. Therefore, the purpose of this study was to investigate the ...adjustment and stabilization strategies of elite college golfers putting under different wind conditions. A 3 D motion analysis system and two force plates were used to record the kinematic and ground reaction force data of the putting stroke in different conditions of wind and putting stance. The artificial wind was produced from an industrial negative pressure fan to create different wind speeds. Participants were asked to perform three putts to the ‘virtual’ hole with a distance of 15 feet under three wind speeds (none, mid, strong) and three stance width conditions. The results revealed that distance control in strong wind conditions was significantly worse. No significant improvement was found in either distance or direction control when using different stance widths for putting under varying wind speeds. While putting under minor or moderate wind conditions, the player can adjust through self-adjustment on movement control to reduce the impact of external wind on putting performance. However, if the wind speed exceeds to certain threshold value (5.5 m/s), the challenges for golfers to maintain postural stability along the antero-posterior axis increased and led to poor putting distance control. Our results suggest that when putting under windy conditions, elite low-handicap college golfers are able adopt a normal stance in order to minimize a change in their putting protocol.
Lift‐to‐lift variability occurs in repetitive lifting tasks due to alterations in the lifting techniques used by the lifter, resulting in variability in lower back tissue loading. Understanding how ...trunk variability changes with time in the initial phases of a lifting bout may provide insights into the risk of injury during work startup. The purpose of this study was to quantify the variation of lifting kinematics and kinetics during the initial phase of a lifting bout. Twenty participants performed a repetitive lifting task continuously for 30 min. The load was equivalent to 10% of each participant's body weight and lifting was done at a rate of six lifts/min. Kinematic variables (three‐dimensional range of motion, angular velocity, and angular acceleration) of the trunk were measured using the Lumbar Motion Monitor and a dynamic biomechanical model estimated peak L5/S1 moment and spine compression. The variances of these variables were compared across 10‐min intervals: 0–10 min, 10–20 min, and 20–30 min. Results indicate a significant reduction in the variance of the peak sagittal acceleration, the sagittal range of motion, the transverse range of motion, peak sagittal moment, and peak spine compression between the first and second time intervals, followed by no significant change in variance between the second and third intervals. The downward trend in variation of these kinematic and kinetic variables suggests an initial adjustment period as the lifters reach a steady state of their lifting technique. The reduced variance of spinal loading may reduce the probability that a tissue tolerance is exceeded.
Abstract Objectives The objective of this study was to assess the effect of occluded vision on lower limb kinematics and kinetics of the knee joint during functional tasks including drop landing ...(single or double leg), squatting (single or double leg), stepping down, cutting movement and hopping in healthy individuals, or individuals who had an ACL reconstruction or deficiency with no vision impairments. Design A systematic review was conducted. Methods A systematic review was conducted and electronic databases were searched between March 2012 and April 2013 for eligible papers. Methodological quality of each study was assessed using the Downs and Black revised checklist. Results Six studies met the eligibility criteria and a wide variation in methodological approaches was reported. This small evidence base indicated equivocal evidence about the effect of vision on knee biomechanics in individuals with healthy and compromised somatosensory function post an ACL reconstruction or injury. Conclusions Clinicians should consider innovative, individualised ACL rehabilitation strategies when prescribing exercises which involve visual occlusion. Further research to increase the relatively small evidence base for the effect of vision on knee biomechanics is warranted.
Characteristics of Gait in Diabetic Foot Ulcer Watanabe, Yoshiteru; Kawabe, Nobuhide
Journal of Japanese Society for Foot Care and Podiatric Medicine,
2022, Letnik:
3, Številka:
2
Journal Article
While the majority of gait research is focused on flat, level surfaces, in everyday life individuals must navigate diverse and changing terrain. Thus it is important to investigate gait patterns on ...multiple surfaces, which is why this dissertation concentrates on hill walking and running as well as the transitions between level and hills. To this end, it was necessary to create a versatile, kinematic-based event detection algorithm that was capable of detecting foot strike and toe off times for multiple gaits at various surface angles. Besides detailing the specific strategies used, we sought to understand how physiological and environmental factors influence the strategies that individuals choose. Many researchers have suggested that the preferred stride frequency (PSF) is determined by mechanical factors. However, this view ignores muscles which are the primary consumers of metabolic energy during running. Thus, we investigated the role of muscle activity in influencing the PSF during downhill running. (Abstract shortened by UMI.)
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