Related Experiment Video
Updated: Jun 4, 2026
08:43
Diagnosis of Musculus Gastrocnemius Tightness - Key Factors for the Clinical Examination
Published on: July 7, 2016
Leg stiffness primarily depends on ankle stiffness during human hopping
1Department of Integrative Biology, University of California, Berkeley 94720-3140, USA. cfarley@socrates.berkeley.edu
Journal of Biomechanics
|March 27, 1999
Summary
Humans adjust leg stiffness by primarily altering ankle stiffness. This finding is crucial for understanding locomotion mechanics and optimizing performance during activities like hopping and running.
Area of Science:
- Biomechanics
- Human Locomotion
- Musculoskeletal Dynamics
Background:
- Humans dynamically adjust leg stiffness to adapt to varying conditions such as stride frequency and surface properties.
- Understanding the specific joint mechanisms underlying these adjustments is key to comprehending human movement control.
Purpose of the Study:
- To investigate the primary mechanisms by which humans adjust leg stiffness during hopping in place.
- To differentiate the contributions of ankle and knee stiffness to overall leg stiffness modulation.
Main Methods:
- Five subjects performed hopping in place at 2.2 Hz, collecting force platform and kinematic data.
- Subjects completed both preferred and maximum height hopping trials.
- A multi-segment computer simulation model was used to analyze the sensitivity of leg stiffness to changes in ankle and knee stiffness.
Main Results:
- Leg stiffness was approximately twofold greater during maximum height hopping compared to preferred height hopping.
- Ankle torsional stiffness increased 1.9-fold, and knee torsional stiffness increased 1.7-fold in maximum height hopping.
- Computer simulations indicated that ankle stiffness adjustments were the primary driver of increased leg stiffness, while knee stiffness changes had minimal impact.
Conclusions:
- The primary mechanism for adjusting leg stiffness during hopping in place is the modulation of ankle joint stiffness.
- This highlights the critical role of the ankle in controlling leg stiffness and, consequently, hopping performance.
Related Concept Videos
00:58Introduction to Joints
The adult human body usually has 206 bones, and except for the hyoid bone in the neck, each bone is connected to at least one other bone. Joints are the location where bones come together. Many joints allow for movement between the bones. At these joints, the articulating surfaces of the adjacent bones can move smoothly against each other. However, the bones of other joints may be joined by connective tissue or cartilage. These joints are designed for stability and provide little or no movement.
01:23Knee Joint
The knee joint is the most complicated joint in the body. It consists of three articulations– two tibiofemoral and one patellofemoral. As is characteristic of synovial joints, the knee joint has a thin articular capsule that partially surrounds this joint cavity. Additionally, several ligaments, muscles, and cartilaginous structures support the movement of the knee.
A total of seven ligaments support the knee joint. The patellar ligament, which is also attached to the quadriceps femoris group...
A total of seven ligaments support the knee joint. The patellar ligament, which is also attached to the quadriceps femoris group...
01:10Ankle Joint
The ankle is formed by the talocrural joint (crural = leg). It consists of the articulations between the talus bone of the foot and the distal ends of the tibia and fibula of the leg. The superior aspect of the talus bone is square-shaped and has three areas of articulation. The top of the talus articulates with the inferior tibia. This is the portion of the ankle joint that carries the body weight between the leg and foot. The sides of the talus are firmly held in position by the articulations...
01:07Development of the Limb Synovial Joints
Joints form during embryonic development in conjunction with the formation and growth of the associated bones. The embryonic tissue that gives rise to all bones, cartilage, and connective tissues of the body is called mesenchyme.
The mesenchymal stem cells differentiate into chondrocytes that form the hyaline cartilage, and later the cartilaginous model of the bone. This model further transforms into a bone. This process is known as endochondral ossification.
During development, the limbs...
The mesenchymal stem cells differentiate into chondrocytes that form the hyaline cartilage, and later the cartilaginous model of the bone. This model further transforms into a bone. This process is known as endochondral ossification.
During development, the limbs...
01:28Muscles of the Leg that Move the Foot and Toes
The human leg comprises an intricate system of muscles that facilitate the movement of feet and toes. Within this system, the muscles are categorized into the anterior, lateral, and posterior compartments, each with a unique set of muscles carrying out specific functions.
Anterior Compartment
The anterior compartment includes muscles that contribute to the dorsiflexion of the foot. This compartment houses the tibialis anterior, extensor hallucis longus, and extensor digitorum longus muscles.
Anterior Compartment
The anterior compartment includes muscles that contribute to the dorsiflexion of the foot. This compartment houses the tibialis anterior, extensor hallucis longus, and extensor digitorum longus muscles.
01:27Movement Joints in Buildings
Movement joints in buildings are essential design elements that accommodate inevitable motions caused by various factors such as temperature changes, moisture content variations, and structural deflections. These motions, if not considered in design and construction, can lead to unsightly or dangerous damage. Movement joints are incorporated in different forms to manage these stresses and allow materials to move without causing distress.
The simplest type of movement joints, working joints, are...
The simplest type of movement joints, working joints, are...