Related Experiment Video
Updated: Jun 16, 2026
07:17
Measurement of Dynamic Force Acted on Water Strider Leg Jumping Upward by the PVDF Film Sensor
Published on: August 3, 2018
Swimming propulsion forces are enhanced by a small finger spread
Daniel A Marinho1, Tiago M Barbosa, Victor M Reis
1Department of Sport Sciences, University of Beira Interior, Covilhã, Portugal.
Journal of Applied Biomechanics
|February 12, 2010
Summary
Slightly spreading fingers in swimming increases drag, potentially enhancing propulsive force. Computational fluid dynamics revealed optimal finger spread for improved swimming performance.
Area of Science:
- Biomechanics
- Fluid Dynamics
Background:
- Swimmer's hand is crucial for propulsion.
- Optimizing hand shape can improve swimming efficiency.
Purpose of the Study:
- Investigate the impact of finger spread on swimming propulsive force.
- Analyze drag and lift forces generated by different finger configurations.
Main Methods:
- Used computational fluid dynamics (CFD) with 3D hand models.
- Simulated varying finger spreads (closed, small, large).
- Analyzed forces at multiple angles of attack.
Main Results:
- A small finger spread (0.32 cm) yielded higher drag coefficients.
- Drag peaked at a 90-degree angle of attack for all models.
- Lift coefficients showed minimal differences across finger spreads.
Conclusions:
- Slight finger spread may enhance propulsive force in swimming.
- Optimizing finger spread is key for maximizing swimming power.
Related Concept Videos
01:39Mechanism of Filopodia Formation
Filopodia are thin, actin-rich cellular protrusions that play an important role in many fundamental cellular functions. They vary in their occurrence, length, and positioning in different cell types, suggesting their diverse roles.
Their main function is to guide migrating cells during normal tissue morphogenesis or cancer metastasis by recognizing and making initial contacts with the extracellular matrix. However, they can also act as stationary cell anchors or help to establish communication...
Their main function is to guide migrating cells during normal tissue morphogenesis or cancer metastasis by recognizing and making initial contacts with the extracellular matrix. However, they can also act as stationary cell anchors or help to establish communication...
01:31Mechanism of Lamellipodia Formation
Cells migrating in response to external stimuli form lamellipodia, which are thin membrane protrusions supported by a mesh of linked, branched, or unbranched actin filaments. These actin filaments interact with myosin motor proteins, creating the dynamic actomyosin complex within the cytoskeleton. Contractility, or the ability to generate contractile stress, is inherent to the actomyosin complex. It helps cells detect the stiffness of the surrounding ECM and exert contractile force for...
01:11Buoyancy and Stability for Submerged and Floating Bodies
In fluid mechanics, buoyancy and stability are key concepts for understanding the behavior of submerged and floating bodies. When a stationary body is fully or partially submerged in a fluid, the fluid exerts a force on the body known as the buoyant force. This force acts vertically upward through a point called the center of buoyancy, which is the center of the displaced fluid volume. According to Archimedes' principle, the magnitude of the buoyant force is equal to the weight of the fluid...
01:20Motor Unit Stimulation
When the neuron of a motor unit fires an action potential, it triggers a series of events, leading to a twitch contraction in the muscle fibers. The process of excitation-contraction coupling is crucial in relaying the action potential to the muscle fibers.
The latent period of contraction marks the onset of excitation-contraction coupling, when the action potential propagates across the sarcolemma, preparing the muscle fibers for contraction. As the fibers enter the contraction phase, the...
The latent period of contraction marks the onset of excitation-contraction coupling, when the action potential propagates across the sarcolemma, preparing the muscle fibers for contraction. As the fibers enter the contraction phase, the...
01:04Hydrostatic Pressure Force on a Curved Surface
Hydrostatic pressure on curved surfaces is a fundamental concept in fluid mechanics with broad applications in the civil engineering field. When fluid is in contact with a curved surface, as in a reservoir, dam, or storage tank, it exerts pressure that varies in magnitude and direction along the curved surface. To assess the total hydrostatic force exerted by the fluid on a curved structure, engineers typically isolate the fluid volume adjacent to the surface and analyze the forces acting on...
01:20Excitation-Contraction Coupling in Skeletal Muscles
Excitation-contraction coupling is a series of events that occur between generating an action potential and initiating a muscle contraction. It occurs at the triad, a structure found in skeletal muscle fibers that comprise a T-tubule and terminal cisternae of the sarcoplasmic reticulum on each side. These triads are visible in longitudinally sectioned muscle fibers. They are typically located at the A-I junction — the junction between the A and I bands of the sarcomere.
When an action potential...
When an action potential...