Victor Forge
Flexion is a movement that results in a decrease in the angle between two or more bones that form a joint. In simpler terms, it involves bending a joint. Muscles contract to produce movement at joints, and flexion is considered the opposite of extension. For example, the biceps brachii muscle is located at the front of the upper arm, and when it contracts, it pulls the bones of the forearm upward, resulting in a decrease in the angle of the elbow. This movement is known as elbow flexion and is used in various daily activities, such as bringing a utensil to the mouth while eating.
| Characteristics | Values |
|---|---|
| Definition | Flexion is a movement that is characterised by a decrease in the angle between two or more bones that form a joint. |
| Example | Bending the elbow joint, bending the knee joint, and bending forward at the waist. |
| Muscles Involved | Biceps Brachii, Brachialis, Brachioradialis, Triceps Brachii, Anconeus, Iliopsoas |
| Opposite Movement | Extension |
| Other Types of Movements | Abduction, Adduction, Rotation, Dorsiflexion, Plantarflexion, Circumduction, Supination |
Explore related products
What You'll Learn
Iliopsoas muscles: Flexion in a sitting position
Flexion is a movement that is characterised by a decrease in the angle between two or more bones that form a joint. In simple terms, it involves bending a joint. For example, the elbow joint is created by the humerus (the bone in the upper arm), ulnar (bone on the pinky side of the forearm), and radius (bone on the thumb side of the forearm). The biceps brachii is the muscle located at the front of the upper arm, and when this muscle contracts, it pulls the bones of the forearm upward, decreasing the angle of the elbow.
The iliopsoas muscle is the primary hip flexor and assists in external rotation of the hip joint. It is essential for correct sitting lumbar posture and plays a critical role during walking and running. The iliopsoas muscle is formed by the psoas and iliacus muscles in the hip. The psoas muscle is a long, ribbon-shaped muscle that runs from the lower back to the groin. There is one psoas muscle on either side of the spine, starting in the lower back just below the ribs, running alongside the spine through the pelvis, and ending near the hips at the top of the femur (thigh bone). The psoas muscle helps move the hips and upper legs and supports posture.
When the iliopsoas muscle contracts, a flexion movement between the trunk and the legs can occur. If the legs are fixed, the trunk will move towards them, as in the last phase of a sit-up; if the trunk is fixed, the legs will move towards it, as when a person is hanging from a bar and bringing the knees up toward the chest. The iliopsoas muscle is by far the most powerful hip flexor and is forcefully engaged in hurdling, high jump, running, javelin throwing, and sit-ups. Without the iliopsoas muscles, flexion in a sitting position is not possible across the horizontal plane.
Muscle Tension Maintenance: Understanding the Intricate Process
You may want to see also
Explore related products
Elbow flexion: Biceps brachii contract, pulling forearm bones upward
Flexion is a movement that is characterised by a decrease in the angle between two or more bones that form a joint. In simpler terms, flexion involves bending a joint. The elbow joint is created by the humerus (a large bone in the upper arm), ulnar (bone on the pinky side of the forearm), and radius (bone on the thumb side of the forearm).
The biceps brachii is the muscle located at the front of the upper arm, and when this muscle contracts, it pulls the bones of the forearm upward. The upward movement of the forearm decreases the angle of the elbow, and this movement is known as elbow flexion. Elbow flexion is used in many daily activities, such as when a person bends their arm to bring a utensil to their mouth while eating.
The elbow joint works as a hinge joint, allowing the arm to bend and straighten through the actions of the biceps brachii and triceps brachii muscles. The biceps brachii muscle performs flexion by pulling on the radius, while the triceps brachii muscle performs extension by pulling on the ulna. The elbow joint is an example of a hinge joint, which allows back-and-forth movement similar to a door hinge. The movement of the elbow involves muscles pulling on the bones of the arm.
The biceps brachii and brachioradialis muscles work together to produce elbow flexion. The activation level of biceps brachii remains constant in all three hand positions, whereas the brachioradialis has a significant increase in pronated hand positions. The brachioradialis has a longer anatomical lever arm than the biceps brachii, so it requires less muscular force to hold an external weight. However, because of its longer lever arm, the brachioradialis demands a stronger contraction to flex the elbow, which is a biomechanical disadvantage.
Muscle Gain: Does Increased Muscle Mean Increased Weight?
You may want to see also
Explore related products
Dorsiflexion: Flexion at the ankle, foot points superiorly
The ankle joint is a hinged synovial joint formed by the articulation of the talus, tibia, and fibula bones. The ankle permits several movements, including dorsiflexion, plantar flexion, inversion, and eversion.
Dorsiflexion is the movement of the foot upwards towards the lower leg, causing an upward bend at the ankle joint. This movement is essential for ambulation, posture, and balance, and it is controlled by the muscles in the anterior compartment of the leg. The main muscles contributing to dorsiflexion are the tibialis anterior, fibularis (peroneus) tertius, extensor digitorum longus, and extensor hallucis longus.
The tibialis anterior is the most superficial and anterior-facing muscle among the dorsiflexors. It sits alongside the lateral border of the extensor digitorum longus. The fibularis (peroneus) tertius muscle has a slim body and extends distally into the space between the fibularis brevis and extensor digitorum longus.
During walking, the ankle dorsiflexors eccentrically contract to control the rotation of the foot and prevent it from slapping the ground. This is known as the ankle rocker phase, where the shank (tibia and fibula) rotates forward around the ankle, allowing forward progression. The dorsiflexion movement is also important in the forefoot rocker phase, where the foot rotates around the forefoot, enabling the foot to clear the ground and avoiding stumbling or tripping.
Damage, weakness, tendonitis, or tears in the muscles or tendons involved in dorsiflexion can have a significant impact on the function and stability of the foot and ankle. For example, weakness in the anterior tibialis can lead to a condition called foot drop, resulting in a dragging of the foot and tripping while walking.
Muscles and Carbs: Understanding the Difference in Body Fuel
You may want to see also
Explore related products
Plantar flexion: Depressing the foot
Plantar flexion is a movement that occurs when the top of the foot points away from the leg, causing the toes to point downwards. This movement is used in many daily activities, such as pressing a car's gas pedal, standing on tiptoes to reach something, or riding a bicycle. It is also used in sports and dance, such as ballet, where it is used to dance en pointe.
This movement is produced by several muscles in the ankle, foot, and leg. The gastrocnemius, which forms half of the calf muscle, is one of the primary muscles involved in plantar flexion. It runs down the back of the lower leg, from the knee to the Achilles tendon in the heel. The soleus, another calf muscle, is also a major player in plantar flexion. Like the gastrocnemius, it connects to the Achilles tendon and is responsible for pushing the foot away from the ground.
The plantaris, a long, thin muscle that runs along the back of the leg, works in conjunction with the Achilles tendon to flex the ankle and knee. The flexor hallucis longus, a deep muscle in the leg, is important for plantar flexion, especially when standing on tiptoes, as it helps to curl the toes. The tibialis posterior, a smaller muscle deep in the lower leg, is involved in plantar flexion and inversion, which is the movement of turning the sole of the foot inward.
The peroneus longus, or fibularis longus, works with the tibialis posterior to stabilise the ankle during tiptoe standing. It is involved in plantar flexion and eversion, which is the movement of turning the sole of the foot outward. The peroneus brevis, or fibularis brevis, is a shorter muscle that lies underneath the peroneus longus and helps maintain foot stability during plantar flexion.
Injuries to the muscles or bones of the ankle can impair plantar flexion, causing swelling and inflammation that restrict movement. Ankle sprains and fractures are common in sports with quick direction changes, like basketball, or activities involving jumping. Treatment for mild ankle sprains typically involves rest, ice, and elevation.
Stabilizing Muscles: The Unsung Heroes of Movement
You may want to see also
Explore related products
Palmar flexion: Extension at the wrist
The wrist is a complex joint that allows the hand to move in almost any direction. The hand and wrist are made up of a network of bones, muscles, nerves, connective tissue, and blood vessels. The wrist acts as a pivot point, allowing the hand to flex and move from side to side.
Palmar flexion refers to the movement of the hand and wrist downwards towards the palm. This is also known as wrist flexion. During palmar flexion, the wrist bends towards the palm, while the fingers, hand, and wrist flex and curl. This movement is enabled by flexor tendons and several muscles.
The muscles that produce palmar flexion include the Flexor Carpi Ulnaris, Flexor Carpi Radialis, Palmaris Longus, and Flexor Digitorum Superficialis. The Flexor Carpi Ulnaris and Flexor Carpi Radialis are long muscles that originate near the elbow and pass through the wrist, attaching to the carpal bones and base of the digits (fingers), respectively. The Palmaris Longus is also a long muscle that originates near the elbow and passes into the wrist, attaching to the base of the hand. The Flexor Digitorum Superficialis lies below the superficial region and is a key muscle controlling wrist and finger flexion.
The wrist also contains several ligaments that support and stabilise the joint. The palmar fascia, for example, is a thick, triangle-shaped ligament-like structure that runs under the skin of the palm. It helps the hand maintain its shape during movement and prevents the skin from sliding when holding objects. The volar carpal ligaments support and stabilise the palmar side of the wrist, while the dorsal radiocarpal ligaments support and stabilise the back of the wrist.
Muscles Protecting Your Ribs: A Comprehensive Guide
You may want to see also
Frequently asked questions
Muscle flexion is a movement that involves a decrease in the angle between two bones that form a joint. In simpler terms, it involves bending a joint.
Examples of muscle flexion include bending the elbow joint, bending the knee joint, and bending forward at the waist.
The biceps brachii is the muscle located at the front of the upper arm. When this muscle contracts, it pulls the bones of the forearm upward, decreasing the angle of the elbow.
Iliopsoas muscles are required for flexion in a sitting position across the horizontal plane.
