Related Experiment Video
Updated: Mar 7, 2026
10:08
Effects of a Novel Neuromuscular Training Intervention on Jump, Sprint, and Change of Direction in Adult Female Soccer Players
Published on: June 10, 2025
1.5K
Plyometric Training Favors Optimizing Muscle-Tendon Behavior during Depth Jumping.
Kuniaki Hirayama1, Soichiro Iwanuma2, Naoki Ikeda3
1Faculty of Sport Sciences, Waseda University Tokorozawa, Japan.
Frontiers in Physiology
|February 10, 2017
Summary
Plyometric training enhances stretch-shortening cycle (SSC) performance by increasing Achilles tendon stiffness and optimizing muscle-tendon mechanics. This leads to improved force production and neuromuscular adjustments during exercises like depth jumps.
Area of Science:
- Biomechanics
- Exercise Physiology
- Sports Science
Background:
- Plyometric training is known to enhance athletic performance.
- The specific mechanisms by which plyometric training improves stretch-shortening cycle (SSC) exercise performance are not fully understood.
- Understanding these adaptations is crucial for optimizing training protocols.
Purpose of the Study:
- To investigate how plyometric training influences muscle strength, tendon stiffness, and muscle-tendon behavior during SSC exercise.
- To elucidate the neuromuscular adaptations contributing to improved SSC performance after plyometric training.
Main Methods:
- Eleven men participated in a 12-week depth jump (DJ) training program targeting the ankle joint.
- Measurements included foot reaction forces, gastrocnemius muscle-tendon behavior, electromyographic (EMG) activity of the triceps surae and tibialis anterior during DJ, maximal static plantar flexion strength, and Achilles tendon stiffness.
- Control group (n=10) did not undergo training.
Main Results:
- Maximal static strength remained unchanged, but Achilles tendon stiffness significantly increased in the training group.
- DJ performance improved, indicated by increased force impulse, shorter ground contact time, and greater reaction force.
- Neuromuscular activity showed increased triceps surae EMG and decreased tibialis anterior EMG during the braking phase.
- During propulsion, triceps surae EMG and gastrocnemius fascicle shortening velocity decreased, while tendon shortening velocity increased.
Conclusions:
- Plyometric training enhances SSC performance primarily through increased tendon stiffness and optimized agonist muscle-tendon interaction, involving altered neuromuscular activity.
- A decrease in antagonist muscle (tibialis anterior) neuromuscular activity during the countermovement phase also contributes to improved performance.
Related Concept Videos
01:27Exercise and Muscle Performance
2.9K
Exercise induces a range of adaptations in muscle tissue, depending on the type and duration of activity. Such physical training can be broadly categorized into two types: endurance exercises and resistance exercises.
Endurance exercises
Endurance exercises involve running, swimming, or cycling, which require repetitive movements with low force output. When a person engages in endurance exercise, a few noticeable changes occur in their skeletal muscles. For instance, the number of capillaries...
Endurance exercises
Endurance exercises involve running, swimming, or cycling, which require repetitive movements with low force output. When a person engages in endurance exercise, a few noticeable changes occur in their skeletal muscles. For instance, the number of capillaries...
2.9K
01:22Muscle Stimulation Frequency
4.9K
The contraction strength of muscles is regulated by motor neurons, which modulate the frequency of action potentials dispatched to the motor units based on the body's requirements. This process of varying the muscle stimulation frequency allows muscles to contract with a force that is precisely tailored to the needs of the moment, whether lifting a feather or a heavy box.
Wave summation
At low firing rates, motor neurons induce individual twitch contractions in muscle fibers. These twitches...
Wave summation
At low firing rates, motor neurons induce individual twitch contractions in muscle fibers. These twitches...
4.9K
01:20Motor Unit Stimulation
4.2K
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...
4.2K
01:20Excitation-Contraction Coupling in Skeletal Muscles
16.7K
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...
When an action...
16.7K
01:22Isotonic and Isometric Muscle Contractions
8.1K
Two primary types of muscle contractions are isotonic and isometric, each serving unique functions and involving distinct mechanisms. Both isotonic and isometric contractions are integral to the body's complex system of movement and stability. Isotonic exercises contribute significantly to functional strength and movement, while isometric contractions are crucial for maintaining posture and joint stability.
Isotonic contractions
Isotonic contractions occur when a muscle changes length while...
Isotonic contractions
Isotonic contractions occur when a muscle changes length while...
8.1K
01:24Generation of Action Potential in Skeletal Muscles
9.8K
Every cell in the body maintains a membrane potential due to an uneven distribution of positive and negative charges across its plasma membrane. The membrane potential is measured in millivolts and quantifies the difference in charge across the membrane.
Like neurons, muscle cells are also regarded as excitable due to their capacity to change in response to stimuli, primarily due to voltage-gated ion channels embedded in their plasma membranes, which get activated by alterations in the...
Like neurons, muscle cells are also regarded as excitable due to their capacity to change in response to stimuli, primarily due to voltage-gated ion channels embedded in their plasma membranes, which get activated by alterations in the...
9.8K