Free vertical moments and transverse forces in human walking and their role in relation to arm-swing

We present force plate data on vertical free moments (force couples in the horizontal plane between the foot and the ground) and on transverse force during unloaded walking in different modes and at different speeds (including running) by adults of both sexes and by children, and examine loaded walking by adult males and one boy. Free moments in slow and normal-speed walking are characterised by a lateral peak in the accelerative phase of stance, but the peak during running, and in some cases of fast walking, occurs in the deceleration phase. Free moments are strongly affected by arm fixation in males, but less so in females. The pattern, but not the scale, of free moments is affected by loading position and side, but load magnitude has little effect if the loaded weight is treated as part of the body. Transverse force is more variable than sagittal force. In males, the transverse force curve shows a marked trough at mid-stance, whereas in females this trough is rarely seen. The transverse force of males also differs from that of females in response to arm fixation, showing a local medial inflection at three-quarters of the stance phase that is not present in females. Adults differ from children younger than 9 years in the presence of a very short, medially directed peak following heel-strike. Analysis of the effects of arm fixation and the timing of forces suggests strongly that arm-swing and free moments tend to reinforce each other in balancing trunk torques induced by the lower limbs. Both are of reduced importance in slow walking.

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Biomechanical Analysis of the Jump Shot in Basketball

Journal of Human Kinetics ◽

10.2478/hukin-2014-0062 ◽

2014 ◽

Vol 42 (1) ◽

pp. 73-79 ◽

Cited By ~ 12

Author(s):

Artur Struzik ◽

Bogdan Pietraszewski ◽

Jerzy Zawadzki

Keyword(s):

Peak Power ◽

High Performance ◽

Force Plate ◽

Lower Limbs ◽

Biomechanical Analysis ◽

Countermovement Jump ◽

Mean Power ◽

Basketball Players ◽

Arm Swing ◽

High Level

Abstract Basketball players usually score points during the game using the jump shot. For this reason, the jump shot is considered to be the most important element of technique in basketball and requires a high level of performance. The aim of this study was to compare the biomechanical characteristics of the lower limbs during a jump shot without the ball and a countermovement jump without an arm swing. The differences between variables provide information about the potential that an athlete can utilise during a game when performing a jump shot. The study was conducted among 20 second-league basketball players by means of a Kistler force plate and the BTS SMART system for motion analysis. The variables measured included the take-off time, mean power, peak power, relative mean power, jump height, maximum landing force and calculated impact ratio. Surprisingly, more advantageous variables were found for the jump shot. This finding suggests a very high performance level in the jump shot in the studied group and a maximum utilisation of their motor abilities. Both types of jumps were characterised by high mean and peak power values and average heights. The high forces at landing, which result in considerable impact ratios, may have prompted the studied group to land softly. Use of the countermovement jump without an arm swing is recommended to assess and predict the progression of player’s jumping ability

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Temporal kinematic and kinetics differences throughout different landing ways following volleyball spike shots

Proceedings of the Institution of Mechanical Engineers Part P Journal of Sports Engineering and Technology ◽

10.1177/17543371211009485 ◽

2021 ◽

pp. 175433712110094

Author(s):

Datao Xu ◽

Jingying Lu ◽

Julien S Baker ◽

Gusztáv Fekete ◽

Yaodong Gu

Keyword(s):

Internal Rotation ◽

Force Plate ◽

Statistical Parametric Mapping ◽

The Body ◽

Lower Limbs ◽

Abduction Angle ◽

Lower Limb Injury ◽

Peak Knee ◽

Volleyball Players ◽

Kinematics And Kinetics

Volleyball players often land on a single leg following a spike shot because of a shift in the center of gravity. This landing is one of the high-risk actions for non-contact ACL injury. The purpose of this study was to compare and analyze the discrete and temporal kinematics and kinetics associated with functional valgus collapse during volleyball in player landing phases during a single-leg landing and double-leg landing following a spike shot. Kinematics and kinetics data were collected (captured by a Vicon motion system and AMTI force plate, processed by Visual-3D software) during the single-leg and double-leg landing phases in 13 semi-professional male volleyball players. The landing phase was defined as initial ground contact (0% landing phase) to maximum knee flexion (100% landing phase). Statistical Parametric Mapping (SPM) analysis revealed that single-leg landing depicted a significantly greater knee abduction angle and hip adduction moment than double-leg landing during the 0%–68% landing phase (single-leg: 7°–16°, double-leg: 0°–9°, p < 0.001) and 18%–22% (single-leg: 0.62–0.91 Nm/kg, double-leg: 0.08–0.19 Nm/kg, p = 0.0063) landing phase, respectively. The traditional discrete analysis revealed that single-leg landing depicted a significantly greater peak knee internal rotation moment (single-leg: 1.46 ± 0.38 Nm/kg, double-leg: 0.79 ± 0.19 Nm/kg, p = 0.006) and peak hip internal rotation moment (single-leg: −2.20 ± 0.54 Nm/kg, double-leg: −0.88 ± 0.30 Nm/kg, p = 0.011) than double-leg landing. Most differences were within a time frame during the landing phase of 30–50 ms in which non-contact ACL injuries are considered to happen. These recorded time frames are consistent with biomechanical measures that are deemed dangerous. To reduce lower limb injury, a volleyball player should consciously swing the arms to influence the body to maintain a better-balanced state. Adjusting the landing mode of the lower limbs can achieve a good cushioning effect during landing following a spike shot.

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Pressure-Sensitive Insoles for Real-Time Gait-Related Applications

Sensors ◽

10.3390/s20051448 ◽

2020 ◽

Vol 20 (5) ◽

pp. 1448 ◽

Cited By ~ 3

Author(s):

Elena Martini ◽

Tommaso Fiumalbi ◽

Filippo Dell’Agnello ◽

Zoran Ivanić ◽

Marko Munih ◽

...

Keyword(s):

Real Time ◽

Center Of Pressure ◽

Pearson Correlation ◽

Reaction Force ◽

Force Plate ◽

Vertical Component ◽

The Body ◽

Heel Strike ◽

Pressure Sensitive ◽

Time Accuracy

Wearable robotic devices require sensors and algorithms that can recognize the user state in real-time, in order to provide synergistic action with the body. For devices intended for locomotion-related applications, shoe-embedded sensors are a common and convenient choice, potentially advantageous for performing gait assessment in real-world environments. In this work, we present the development of a pair of pressure-sensitive insoles based on optoelectronic sensors for the real-time estimation of temporal gait parameters. The new design makes use of a simplified sensor configuration that preserves the time accuracy of gait event detection relative to previous prototypes. The system has been assessed relatively to a commercial force plate recording the vertical component of the ground reaction force (vGRF) and the coordinate of the center of pressure along the so-called progression or antero-posterior plane (CoPAP) in ten healthy participants during ground-level walking at two speeds. The insoles showed overall median absolute errors (MAE) of 0.06 (0.02) s and 0.04 (0.02) s for heel-strike and toe-off recognition, respectively. Moreover, they enabled reasonably accurate estimations of the stance phase duration (2.02 (2.03) % error) and CoPAP profiles (Pearson correlation coefficient with force platform ρCoP = 0.96 (0.02)), whereas the correlation with vGRF measured by the force plate was lower than that obtained with the previous prototype (ρvGRF = 0.47 (0.20)). These results confirm the suitability of the insoles for online sensing purposes such as timely gait phase estimation and discrete event recognition.

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Bio-Inspired Take-Off Maneuver and Control in Vertical Jumping for Quadruped Robot with Manipulator

Micromachines ◽

10.3390/mi12101189 ◽

2021 ◽

Vol 12 (10) ◽

pp. 1189

Author(s):

Ru Kang ◽

Fei Meng ◽

Lei Wang ◽

Xuechao Chen ◽

Zhangguo Yu ◽

...

Keyword(s):

Degrees Of Freedom ◽

Control Method ◽

Quadruped Robot ◽

The Body ◽

Lower Limbs ◽

Whole Body ◽

Hierarchical Optimization ◽

Arm Swing ◽

Joint Torques ◽

Exploration Environment

The jumping motion of legged robots is an effective way to overcome obstacles in the rugged microgravity planetary exploration environment. At the same time, a quadruped robot with a manipulator can achieve operational tasks during movement, which is more practical. However, the additional manipulator will restrict the jumping ability of the quadruped robot due to the increase in the weight of the system, and more active degrees of freedom will increase the control complexity. To improve the jumping height of a quadruped robot with a manipulator, a bio-inspired take-off maneuver based on the coordination of upper and lower limbs is proposed in this paper. The kinetic energy and potential energy of the system are increased by driving the manipulator-end (ME) to swing upward, and the torso driven by the legs will delay reaching the required peak speed due to the additional load caused by the accelerated ME. When the acceleration of ME is less than zero, it will pull the body upward, which reduces the peak power of the leg joints. Therefore, the jumping ability of the system is improved. To realize continuous and stable jumping, a control framework based on whole-body control was established, in which the quadruped robot with a manipulator was a simplified floating seven-link model, and the hierarchical optimization was used to solve the target joint torques. This method greatly simplifies the dynamic model and is convenient for calculation. Finally, the jumping simulations in different gravity environments and a 15° slope were performed. The jump heights have all been improved after adding the arm swing, which verified the superiority of the bio-inspired take-off maneuver proposed in this paper. Furthermore, the stability of the jumping control method was testified by the continuous and stable jumping.

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Aspergillus Spondylodiscitis After Spinal Stenosis Surgery: A Case Report

Iranian Journal of Neurosurgery ◽

10.32598/irjns.5.3.9 ◽

2020 ◽

Vol 5 (3 And 4) ◽

pp. 155-160

Author(s):

Mohsen Aghapoor ◽

◽

Babak Alijani Alijani ◽

Mahsa Pakseresht-Mogharab ◽

◽

...

Keyword(s):

Antifungal Drugs ◽

The Body ◽

Lower Limbs ◽

Lumbar Pain ◽

Case Presentation ◽

Delay In Diagnosis ◽

Death Case ◽

Therapeutic Results ◽

History Of ◽

Probable Diagnosis

Background and Importance: Spondylodiscitis is an inflammatory disease of the body of one or more vertebrae and intervertebral disc. The fungal etiology of this disease is rare, particularly in patients without immunodeficiency. Delay in diagnosis and treatment of this disease can lead to complications and even death. Case Presentation: A 63-year-old diabetic female patient, who had a history of spinal surgery and complaining radicular lumbar pain in both lower limbs with a probable diagnosis of spondylodiscitis, underwent partial L2 and complete L3 and L4 corpectomy and fusion. As a result of pathology from tissue biopsy specimen, Aspergillus fungi were observed. There was no evidence of immunodeficiency in the patient. The patient was treated with Itraconazole 100 mg twice a day for two months. Pain, neurological symptom, and laboratory tests improved. Conclusion: The debridement surgery coupled with antifungal drugs can lead to the best therapeutic results.

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Size-At-Age Variability and Sexual Dimorphism of Morphometric Characteristics in the Late Ontogenesis of the Marsh Frog, Pelophylax Ridibundus (Anura, Ranidae), from Terrytory of Crimea

Vestnik Zoologii ◽

10.2478/vzoo-2019-0031 ◽

2019 ◽

Vol 53 (4) ◽

pp. 325-334

Author(s):

V. N. Peskov ◽

N. A. Petrenko ◽

V. Yu. Reminnyi

Keyword(s):

Age Groups ◽

The Body ◽

Adult Males ◽

Morphometric Characteristics ◽

Morphometric Characters ◽

Mean Values ◽

Marsh Frog ◽

Males And Females ◽

Size At Age ◽

Linear Body

Abstract We study size-at-age and sexual variability of morphometric characteristics of the marsh frog. According to the size of the body, males were divided into three size-age groups (juvenis, subadultus, adultus), females — into four groups (juvenis, subadultus, adultus, adultus-I). We found that the chronological age of frogs (skeletochronology) does not always correspond to their biological age (size and proportions of the body). We noted that the semi-adult males are reliably larger than females by mean values of 26 studied morphometric characters. Males and females of “adultus” group do not differ by linear body size, significant differences were found in body proportions (7 characters). For the females of “adultus-I” group, the mean values of 26 characters are significantly larger than for “adultus” males. The results of our study showed that with the age of the marsh frog, the level of exhibition, directionality and structure of morphometric sex differences changes.

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Correction of Posture Deviations in the Sagittal Plane Using the Pilates Method

SPORT AND SOCIETY ◽

10.36836/uaic/fefs/10.50 ◽

2019 ◽

pp. 3-13

Author(s):

Alexandru Cîtea ◽

George-Sebastian Iacob

Keyword(s):

Low Back Pain ◽

Back Pain ◽

Postural Control ◽

Human Body ◽

Sagittal Plane ◽

The Body ◽

Lower Limbs ◽

Low Back ◽

Pilates Method ◽

The Relationship

Posture is commonly perceived as the relationship between the segments of the human body upright. Certain parts of the body such as the cephalic extremity, neck, torso, upper and lower limbs are involved in the final posture of the body. Musculoskeletal instabilities and reduced postural control lead to the installation of nonstructural posture deviations in all 3 anatomical planes. When we talk about the sagittal plane, it was concluded that there are 4 main types of posture deviation: hyperlordotic posture, kyphotic posture, rectitude and "sway-back" posture.Pilates method has become in the last decade a much more popular formof exercise used in rehabilitation. The Pilates method is frequently prescribed to people with low back pain due to their orientation on the stabilizing muscles of the pelvis. Pilates exercise is thus theorized to help reactivate the muscles and, by doingso, increases lumbar support, reduces pain, and improves body alignment.

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Ileal transposition helps to regulate plasma hepatokine levels in obese Zucker (Crl:ZUC(ORL)-Leprfa) rats

Scientific Reports ◽

10.1038/s41598-021-87293-w ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Dominika Stygar ◽

Tomasz Sawczyn ◽

Agnieszka Dulska ◽

Elżbieta Chełmecka ◽

Łukasz Mielańczyk ◽

...

Keyword(s):

Body Weight ◽

Plasma Levels ◽

Plasma Concentrations ◽

The Body ◽

Retinol Binding Protein ◽

Fibroblast Growth Factor 21 ◽

Adult Males ◽

Total Lipids ◽

Ileal Transposition ◽

Sham Surgery

AbstractWe studied the long-term effect of ileal transposition (IT) metabolic surgery on the hepatokines: retinol-binding protein-4 (RBP4), α-2-HS-glycoprotein (aHSG/fetuin-A), and fibroblast growth factor 21 (FGF21), C-reactive protein (CRP) plasma levels, glucose metabolism, body weight, liver histology, as well as total lipids concentration in muscle, liver, and fat tissue of obese Zucker (Crl:ZUC(ORL)-Leprfa) rats. 14 adult males were randomly submitted either to IT or SHAM (control) surgery. Pre-operative hepatokines plasma levels were not significantly different in rats submitted to IT or SHAM protocol. Three months after the procedures the plasma levels of RBP4, aHSG, FGF21, and CRP were significantly lower in IT-operated animals when compared to SHAM-operated group. Three and 12 weeks after the IT and SHAM surgery, the AUCOGTT were significantly lower than AUCOGTT before the surgery. HOMA-IR was lower in rats after IT surgery in comparison to the SHAM-operated rats. Muscle and liver total lipids concentration was reduced after the IT procedure when compared to pre-IT conditions. IT had a significant reductive impact on the body weight in comparison to SHAM surgery in the 4th, 6th, 8th, and 10th week after the surgery. We conclude that IT reduces hepatokines’ plasma concentrations, muscle and liver total lipids concentration but not the inflammatory processes in the liver of Zucker (Crl:ZUC(ORL)-Leprfa) rats.

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A Feasibility Study of Kinematic Characteristics on the Upper Body According to the Shooting of Elite Disabled Archery Athletes

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18062962 ◽

2021 ◽

Vol 18 (6) ◽

pp. 2962

Author(s):

Tae-Whan Kim ◽

Jae-Won Lee ◽

Seoung-Ki Kang ◽

Kyu-Yeon Chae ◽

Sang-Hyup Choi ◽

...

Keyword(s):

The Body ◽

Lower Limbs ◽

Upper Body ◽

Movement Trajectory ◽

Phase 2 ◽

Kinematic Characteristics ◽

Significant Difference ◽

Athletes With Disabilities ◽

Body Center ◽

Time Required

The purpose of this study is to compare and analyze the kinematic characteristics of the upper limb segments during the archery shooting of Paralympic Wheelchair Class archers (ARW2—second wheelchair class—paraplegia or comparable disability) and Paralympic Standing Class archers (ARST—standing archery class—loss of 25 points in the upper limbs or lower limbs), where archers are classified according to their disability grade among elite disabled archers. The participants of this study were selected as seven elite athletes with disabilities by the ARW2 (n = 4) and ARST (n = 3). The analysis variables were (1) the time required for each phase, (2) the angle of inclination of the body center, (3) the change of trajectory of body center, and (4) the change of the movement trajectory of the bow center by phase when performing six shots in total. The ARW2 group (drawing phase; M = 2.228 s, p < 0.05, holding phase; M = 4.414 s, p < 0.05) showed a longer time than the ARST group (drawing phase; M = 0.985 s, holding phase; M = 3.042 s), and the angle of the body did not show a significant difference between the two groups. Additionally, in the direction of the anteroposterior axis in the drawing phase, the change in the movement trajectory of the body center showed a more significant amount of change in the ARW2 group than in the ARST group, and the change in the movement trajectory of the bow center did not show a significant difference between the two groups.

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The Influence of Countermovement Jump Protocol on Reactive Strength Index Modified and Flight Time: Contraction Time in Collegiate Basketball Players

Sports ◽

10.3390/sports7020037 ◽

2019 ◽

Vol 7 (2) ◽

pp. 37 ◽

Cited By ~ 3

Author(s):

Aaron Heishman ◽

Brady Brown ◽

Bryce Daub ◽

Ryan Miller ◽

Eduardo Freitas ◽

...

Keyword(s):

Force Plate ◽

Flight Time ◽

Contraction Time ◽

Strength Index ◽

Countermovement Jump ◽

Basketball Players ◽

Arm Swing ◽

Collegiate Basketball ◽

Positive Correlations ◽

The Relationship

The purpose of the present investigation was to evaluate differences in Reactive Strength Index Modified (RSIMod) and Flight Time to Contraction Time Ratio (FT:CT) during the countermovement jump (CMJ) performed without the arm swing (CMJNAS) compared to the CMJ with the arm swing (CMJAS), while exploring the relationship within each variable between jump protocols. A secondary purpose sought to explore the relationship between RSIMod and FT:CT during both jump protocols. Twenty-two collegiate basketball players performed both three CMJNAS and three CMJAS on a force plate, during two separate testing sessions. RSIMod was calculated by the flight-time (RSIModFT) and impulse-momentum methods (RSIModIMP). CMJ variables were significantly greater during the CMJAS compared to CMJNAS (p < 0.001). There were large to very large correlations within each variable between the CMJAS and CMJNAS. There were significant positive correlations among RSIModFT, RSIModIMP, and FT:CT during both the CMJAS (r ≥ 0.864, p < 0.001) and CMJNAS (r ≥ 0.960, p < 0.001). These findings identify an increase in RSIMod or FT:CT during the CMJAS, that may provide independent information from the CMJNAS. In addition, either RSIMod or FT:CT may be utilized to monitor changes in performance, but simultaneous inclusion may be unnecessary.

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