Small changes in ball position at address cause a chain effect in golf swing

AbstractThe purpose of this study was to investigate how the ball position along the mediolateral (M-L) direction of a golfer causes a chain effect in the ground reaction force, body segment and joint angles, and whole-body centre of mass during the golf swing. Twenty professional golfers were asked to complete five straight shots for each 5 different ball positions along M-L: 4.27 cm (ball diameter), 2.14 cm (ball radius), 0 cm (reference position at preferred ball position), – 2.14 cm, and – 4.27 cm, while their ground reaction force and body segment motions were captured. The dependant variables were calculated at 14 swing events from address to impact, and the differences between the ball positions were evaluated using Statistical Parametric Mapping. The left-sided ball positions at address showed a greater weight distribution on the left foot with a more open shoulder angle compared to the reference ball position, whereas the trend was reversed for the right-sided ball positions. These trends disappeared during the backswing and reappeared during the downswing. The whole-body centre of mass was also located towards the target for the left-sided ball positions throughout the golf swing compared to the reference ball position, whereas the trend was reversed for the right-sided ball positions. We have concluded that initial ball position at address can cause a series of chain effects throughout the golf swing.

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Balancing on a narrow ridge: biomechanics and control

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.1999.0439 ◽

1999 ◽

Vol 354 (1385) ◽

pp. 869-875 ◽

Cited By ~ 61

Author(s):

E. Otten

Keyword(s):

Hip Joint ◽

Ground Reaction Force ◽

Inverted Pendulum ◽

Reaction Force ◽

Angular Acceleration ◽

Centre Of Mass ◽

Inverted Pendulum Model ◽

Pendulum Model ◽

Narrow Ridge ◽

Standing Humans

The balance of standing humans is usually explained by the inverted pendulum model. The subject invokes a horizontal ground–reaction force in this model and controls it by changing the location of the centre of pressure under the foot or feet. In experiments I showed that humans are able to stand on a ridge of only a few millimetres wide on one foot for a few minutes. In the present paper I investigate whether the inverted pendulum model is able to explain this achievement. I found that the centre of mass of the subjects sways beyond the surface of support, rendering the inverted pendulum model inadequate. Using inverse simulations of the dynamics of the human body, I found that hip–joint moments of the stance leg are used to vary the horizontal component of the ground–reaction force. This force brings the centre of mass back over the surface of support. The subjects generate moments of force at the hip–joint of the swing leg, at the shoulder–joints and at the neck. These moments work in conjunction with a hip strategy of the stance leg to limit the angular acceleration of the head–arm–trunk complex. The synchrony of the variation in moments suggests that subjects use a motor programme rather than long latency reflexes.

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Biomechanics Differ for Individuals With Similar Self-Reported Characteristics of Patellofemoral Pain During a High-Demand Multiplanar Movement Task

Journal of Sport Rehabilitation ◽

10.1123/jsr.2020-0220 ◽

2020 ◽

pp. 1-10

Author(s):

Matthew K. Seeley ◽

Seong Jun Son ◽

Hyunsoo Kim ◽

J. Ty Hopkins

Keyword(s):

Ground Reaction Force ◽

Injury Risk ◽

Reaction Force ◽

Patellofemoral Pain ◽

Joint Torque ◽

Whole Body ◽

Ground Contact ◽

High Demand ◽

Contact Phase ◽

Hip Extension

Context: Patellofemoral pain (PFP) is often categorized by researchers and clinicians using subjective self-reported PFP characteristics; however, this practice might mask important differences in movement biomechanics between PFP patients. Objective: To determine whether biomechanical differences exist during a high-demand multiplanar movement task for PFP patients with similar self-reported PFP characteristics but different quadriceps activation levels. Design: Cross-sectional design. Setting: Biomechanics laboratory. Participants: A total of 15 quadriceps deficient and 15 quadriceps functional (QF) PFP patients with similar self-reported PFP characteristics. Intervention: In total, 5 trials of a high-demand multiplanar land, cut, and jump movement task were performed. Main Outcome Measures: Biomechanics were compared at each percentile of the ground contact phase of the movement task (α = .05) between the quadriceps deficient and QF groups. Biomechanical variables included (1) whole-body center of mass, trunk, hip, knee, and ankle kinematics; (2) hip, knee, and ankle kinetics; and (3) ground reaction forces. Results: The QF patients exhibited increased ground reaction force, joint torque, and movement, relative to the quadriceps deficient patients. The QF patients exhibited: (1) up to 90, 60, and 35 N more vertical, posterior, and medial ground reaction force at various times of the ground contact phase; (2) up to 4° more knee flexion during ground contact and up to 4° more plantarflexion and hip extension during the latter parts of ground contact; and (3) up to 26, 21, and 48 N·m more plantarflexion, knee extension, and hip extension torque, respectively, at various times of ground contact. Conclusions: PFP patients with similar self-reported PFP characteristics exhibit different movement biomechanics, and these differences depend upon quadriceps activation levels. These differences are important because movement biomechanics affect injury risk and athletic performance. In addition, these biomechanical differences indicate that different therapeutic interventions may be needed for PFP patients with similar self-reported PFP characteristics.

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Number of Trials for the Reliable Golf Swing Ground Reaction Force Data Collection and Its Characteristics

Korean Journal of Sport Biomechanics ◽

10.5103/kjsb.2007.17.4.115 ◽

2007 ◽

Vol 17 (4) ◽

pp. 115-125 ◽

Cited By ~ 1

Keyword(s):

Data Collection ◽

Ground Reaction Force ◽

Reaction Force ◽

Golf Swing ◽

Force Data

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Does Delivery Length Impact Measures of Whole-Body Biomechanical Load During Pace Bowling?

International Journal of Sports Physiology and Performance ◽

10.1123/ijspp.2019-0622 ◽

2020 ◽

Vol 15 (10) ◽

pp. 1485-1489

Author(s):

Samuel J. Callaghan ◽

Robert G. Lockie ◽

Walter Yu ◽

Warren A. Andrews ◽

Robert F. Chipchase ◽

...

Keyword(s):

Ground Reaction Force ◽

Repeated Measures ◽

Reaction Force ◽

Practical Importance ◽

Whole Body ◽

Loading Rates ◽

Biomechanical Loading ◽

Repeated Measures Analysis ◽

Load Monitoring ◽

Monitoring Practice

Purpose: To investigate whether changes in delivery length (ie, short, good, and full) lead to alterations in whole-body biomechanical loading as determined by ground reaction force during front-foot contact of the delivery stride for pace bowlers. Current load-monitoring practices of pace bowling in cricket assume equivocal biomechanical loading as only the total number of deliveries are monitored irrespective of delivery length. Methods: A total of 16 male pace bowlers completed a 2-over spell at maximum intensity while targeting different delivery lengths (short, 7–10 m; good, 4–7 m; and full, 0–4 m from the batter’s stumps). In-ground force plates were used to determine discrete (vertical and braking force, impulse, and loading rates) and continuous front-foot contact ground reaction force. Repeated-measures analysis of variance (P < .05), effects size, and statistical parametrical mapping were used to determine differences between delivery lengths. Results: There were no significant differences between short, good, and full delivery lengths for the discrete and continuous kinetic variables investigated (P = .19–1.00), with trivial to small effect sizes. Conclusion: There were minimal differences in front-foot contact biomechanics for deliveries of different lengths (ie, short, good, and full). These data reinforce current pace bowling load-monitoring practices (ie, counting the number of deliveries), as changes in delivery length do not affect the whole-body biomechanical loading experienced by pace bowlers. This is of practical importance as it retains simplicity in load-monitoring practice that is used widely across different competition levels and ages.

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Associations between ground reaction force waveforms and sprint start performance

International Journal of Sports Science & Coaching ◽

10.1177/1747954119874887 ◽

2019 ◽

Vol 14 (5) ◽

pp. 658-666 ◽

Cited By ~ 2

Author(s):

Steffi L Colyer ◽

Philip Graham-Smith ◽

Aki IT Salo

Keyword(s):

Reaction Force ◽

Statistical Parametric Mapping ◽

Force Production ◽

Mass Motion ◽

Ground Reaction Forces ◽

Centre Of Mass ◽

Specific Training ◽

Force Vector ◽

Reaction Forces ◽

External Power

Ground reaction forces produced on the blocks determine an athlete’s centre of mass motion during the sprint start, which is crucial to sprint performance. This study aimed to understand how force waveforms are associated with better sprint start performance. Fifty-seven sprinters (from junior to world elite) performed a series of block starts during which the ground reaction forces produced by the legs and arms were separately measured. Statistical parametric mapping (linear regression) revealed specific phases of these waveforms where forces were associated with average horizontal external power. Better performances were achieved by producing higher forces and directing the force vector more horizontally during the initial parts of the block phase (17–34% and 5–37%, respectively). During the mid-push (around the time of rear block exit: ∼54% of the block push), magnitudes of front block force differentiated performers, but orientation did not. Consequently, the ability to sustain high forces during the transition from bilateral to unilateral pushing was a performance-differentiating factor. Better athletes also exhibited a higher ratio of forces on the front block in the latter parts of unilateral pushing (81–92% of the block push), which seemed to allow these athletes to exit the blocks with lower centre of mass projection angles. Training should reflect these kinetic requirements, but also include technique-based aspects to increase both force production and orientation capacities. Specific training focused on enhancing anteroposterior force production during the transition between double- to single-leg propulsion could be beneficial for overall sprint start performance.

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The Ground Reaction Force Analysis during Golf Swing on the Slopes

Korean Journal of Sport Biomechanics ◽

10.5103/kjsb.2008.18.1.191 ◽

2008 ◽

Vol 18 (1) ◽

pp. 191-201

Keyword(s):

Ground Reaction Force ◽

Reaction Force ◽

Golf Swing ◽

Force Analysis

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EVALUATION OF A COMPUTER-SIMULATION MODEL FOR HUMAN AMBULATION ON STILTS

Journal of Mechanics in Medicine and Biology ◽

10.1142/s0219519404001041 ◽

2004 ◽

Vol 04 (03) ◽

pp. 283-303 ◽

Cited By ~ 3

Author(s):

CHRISTOPHER S. PAN ◽

KIMBERLY M. MILLER ◽

SHARON CHIOU ◽

JOHN Z. WU

Keyword(s):

Computer Simulation ◽

Ground Reaction Force ◽

Center Of Mass ◽

Reaction Force ◽

Construction Workers ◽

Whole Body ◽

Vertical Ground Reaction Force ◽

Actual Measurement ◽

Increased Risk ◽

Vertical Ground

Stilts are elevated tools that are frequently used by construction workers to raise workers 18 to 40 inches above the ground without the burden of erecting scaffolding or a ladder. Some previous studies indicated that construction workers perceive an increased risk of injury when working on stilts. However, no in-depth biomechanical analyses have been conducted to examine the fall risks associated with the use of stilts. The objective of this study is to evaluate a computer-simulation stilts model. Three construction workers were recruited for walking tasks on 24-inch stilts. The model was evaluated using whole body center of mass and ground reaction forces. A PEAK™ motion system and two Kistler™ force platforms were used to collect data on both kinetic and kinematic measures. Inverse- and direct-dynamics simulations were performed using a model developed using commercial software — ADAMS and LifeMOD. For three coordinates (X, Y, Z) of the center of mass, the results of univariate analyses indicated very small variability for the mean difference between the model predictions and the experimental measurements. The results of correlation analyses indicated similar trends for the three coordinates. Plotting the resultant and vertical ground reaction force for both right and left feet showed small discrepancies, but the overall shape was identical. The percentage differences between the model and the actual measurement for three coordinates of the center of mass, as well as resultant and vertical ground reaction force, were within 20%. This newly-developed stilt walking model may be used to assist in improving the design of stilts.

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Short-term results of gait analysis with the Heidelberg foot measurement method and functional outcome after operative treatment of ankle fractures

Journal of Foot and Ankle Research ◽

10.1186/s13047-021-00505-4 ◽

2022 ◽

Vol 15 (1) ◽

Author(s):

Jessica C. Böpple ◽

Michael Tanner ◽

Sarah Campos ◽

Christian Fischer ◽

Sebastian Müller ◽

...

Keyword(s):

Gait Analysis ◽

Ground Reaction Force ◽

Measurement Method ◽

Reaction Force ◽

Statistical Parametric Mapping ◽

Ankle Fractures ◽

Parametric Mapping ◽

Healthy Participants ◽

Over Time ◽

Dorsal Flexion

Abstract Background Ankle fractures are common fractures in trauma surgery. Several studies have compared gait patterns between affected patients and control groups. However, no one used the Heidelberg Foot Measurement Method in combination with statistical parametric mapping of the entire gait cycle in this patient cohort. We sought to identify possible mobility deficits in the tibio-talar joint and medial arch in patients after ankle fractures as a sign of stiffness and pain that could result in a pathological gait pattern. We focused on the tibio-talar flexion as it is the main movement in the tibio-talar joint. Moreover, we examined the healing progress over time. Methods Fourteen patients with isolated ankle fractures were included prospectively. A gait analysis using the Heidelberg Foot Measurement Method was performed 9 and 26 weeks after surgery to analyse the tibio-talar dorsal flexion, the foot tibia dorsal flexion, the subtalar inversion and the medial arch as well as the cadence, the walking speed and the ground reaction force. The American Orthopedic Foot & Ankle Society ankle hindfoot score was used to obtain clinical data. Results were compared to those from 20 healthy participants. Furthermore, correlations between the American Orthopedic Foot & Ankle Society hindfoot score and the results of the gait analysis were evaluated. Results Statistical parametric mapping showed significant differences for the Foot Tibia Dorsal Flexion for patients after 9 weeks (53–75%: p = 0.001) and patients after 26 weeks (58–70%: p = 0.011) compared to healthy participants, respectively. Furthermore, significant differences regarding the tibio-talar dorsal flexion for patients 9 weeks after surgery (15–40%: p < 0.001; 56,5–70%: p = 0.007; 82–88%: p = 0.033; 97–98,5%: p = 0.048) as well as patients after 26 weeks (62,5–65%: p = 0.049) compared to healthy participants, respectively. There were no significant differences looking at the medial arch and the subtalar inversion. Moreover, significant differences regarding the ground reaction force were found for patients after 9 weeks (0–17%: p < 0.001; 21–37%: p < 0.001; 41–54%: p < 0.001; 60–64%: p = 0.013) as well as patients after 26 weeks (0–1,5%: p = 0.046; 5–15%: p < 0.001; 27–33%: p = 0.001; 45–49%: p = 0.005; 57–59%: p = 0.049) compared to healthy participants, respectively. In total, the range of motion in the tibio-talar joint and the medial arch was reduced in affected patients compared to healthy participants. Patients showed significant increase of the range of motion between 9 and 26 weeks. Conclusions This study shows, that patients affected by ankle fractures show limited mobility in the tibio-talar joint and the medial arch when compared to healthy participants. Even though the limitation of motion remains at least over a period of 26 weeks, a significant increase can be recognized over time. Furthermore, if we look at the absolute values, the patients’ values tend to get closer to those of the control group. Trial registration This study is registered at the German Clinical Trials Register (DRKS00023379).

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