basics

Muscle is a dumb organ, uses secretions as a signal. More for tendon. (muscles to bones via tendons)

Tendons are for measuring weight. Signals for how much force to use for tendon. (muscle to bones)

Ligament for range of motion and limits how far you stretch out. (bones to bones)

Joints are an additional layer to wrap fluid. allow bones to move with stability and support. (bones to bones)

Cartilage/bursa (fluid sac) is for protection - cushion (between bones and muscles)

Bone is a frame/structure, weight bearing (bones to ligaments and to muscles via tendons)

Nerve sends/receives signals (brain and spinal cord to muscles, organs, sensory receptors)

Blood vessel - sends blood (small branches of arteries to small branches of veins)

Muscles connect to bones via tendons, which are tough, fibrous tissues that transmit the force of muscle contraction to the bones, allowing for movement.
Here's a more detailed explanation:
- Tendons:
  These are the key connectors, acting as strong cords or sheets of connective tissue that attach muscles to bones.
- Muscle Function:
  When muscles contract (shorten), they pull on the tendons, which in turn pull on the attached bones, causing movement at the joints.
- Examples:
  Think of your biceps muscle in your upper arm; it's attached to the bones of your forearm via tendons, allowing you to flex your elbow and lift objects.
- Other Connective Tissues:
  While tendons connect muscles to bones, ligaments are another type of connective tissue that connect bone to bone, providing stability to joints.
Tendons, which are tough, fibrous tissues, connect muscles to bones, enabling movement by transmitting the forces generated by muscles to the skeletal system.
Here's a more detailed explanation:
- Function:
  Tendons act as a bridge, transferring the force of muscle contraction to the bones, allowing us to move.
- Structure:
  They are composed of dense fibrous connective tissue, primarily made up of collagen.
- Location:
  Tendons are found throughout the body, connecting muscles to bones in various locations, such as the shoulder, elbow, wrist, knee, and ankle.
- Difference from Ligaments:
  While tendons connect muscles to bones, ligaments connect bones to other bones, providing stability to joints.
- Injuries:
  Tendons can be injured, leading to conditions like strains, tendinitis, and tears.
Ligaments are tough, fibrous connective tissues that connect bone to bone, playing a crucial role in stabilizing and supporting joints.
Here's a more detailed explanation:
- What ligaments do:
  Ligaments help hold bones together at joints, preventing excessive movement and providing stability.
- Where ligaments are found:
  Ligaments are found throughout the body, especially in and around joints like the knee, ankle, and wrist.
- Ligaments vs. tendons:
  While ligaments connect bone to bone, tendons connect muscles to bone, allowing for movement.
- Structure of ligaments:
  Ligaments are made up of dense bundles of collagen fibers, which are tough and flexible.
- Anatomy of ligaments:
  The basic building blocks of a ligament are collagen fibers. These fibers are usually arranged in parallel bundles and attached to the outer covering that surrounds all bones, the periosteum.
- Ligaments at joints:
  In a synovial joint, such as the knee, ligaments form a capsular sac that encloses the articulating bone ends and a lubricating membrane, the synovial membrane.
Joints connect bones in the body. They allow bones to move, and also provide stability and support for the skeleton.
What joints connect?
- Elbows and hips: Freely movable joints, also known as synovial joints
- Spine: Partially movable joints, also known as cartilaginous joints
- Skull: Immovable joints, also known as fibrous joints
- Knee: Supported by ligaments that prevent twisting
- Teeth and sockets: Immovable joints, also known as gomphoses
- Tibia and fibula: Slightly movable joints, also known as syndesmoses
How do joints work?
Joints are made up of cartilage, ligaments, tendons, bursas, and synovial fluid.
- Cartilage: Covers the surface of bones to reduce friction
- Ligaments: Connect bones and limit movement
- Tendons: Connect muscles to bones
- Bursas: Fluid-filled sacs that cushion friction
- Synovial fluid: Lubricates the joint
Types of joints
The type of joint depends on how much it can move. The more a joint can move, the greater the risk of injury.
Cartilage is a connective tissue that connects bones, muscles, and other structures in the body. Specifically, it connects:
- Bones:
  Cartilage covers the ends of bones in joints, providing a smooth surface for movement and cushioning impact.
- Muscles to bones:
  Tendons are made of fibrous connective tissue and connect muscles to bones.
- Ligaments to bones:
  Ligaments are also made of fibrous connective tissue and connect bone to bone.
- Other tissues:
  Cartilage can also connect other tissues together, such as in the ears and nose.
Bones connect to other bones via ligaments, which are strong bands of tissue, and to muscles via tendons, which are also strong, fibrous tissues.
Here's a more detailed explanation:
- Ligaments:
  These are strong, fibrous tissues that connect bone to bone, particularly at joints, helping to stabilize and hold them together.
- Tendons:
  These are also strong, fibrous tissues that connect muscles to bones, allowing muscles to pull on bones and cause movement.
- Joints:
  Joints are the areas where two or more bones meet and allow for movement
- Cartilage:
  Cartilage is a strong, flexible tissue that cushions the ends of bones in joints, acting as a shock absorber
Nerves connect the brain and spinal cord (the central nervous system) to the rest of the body, including muscles, organs, and sensory receptors, enabling communication and control of bodily functions.
Here's a more detailed explanation:
- Central Nervous System (CNS): The brain and spinal cord form the CNS, the body's control center.
- Peripheral Nervous System (PNS): The PNS is a network of nerves that branch out from the spinal cord, connecting the CNS to the rest of the body.
- Nerve Functions:
  - Sensory Nerves: Carry information from sensory receptors (like in the skin, muscles, and organs) to the brain and spinal cord, allowing us to feel sensations like touch, pain, temperature, and position.
  - Motor Nerves: Carry signals from the brain and spinal cord to muscles and glands, enabling movement and controlling bodily functions.
  - Cranial Nerves: Connect the brain directly to parts of the head, face, eyes, ears, nose, and throat.
  - Spinal Nerves: Connect the spinal cord to the rest of the body, including the limbs, organs, and skin.
- Autonomic Nervous System: A part of the PNS that controls involuntary functions like heart rate, breathing, and digestion.
- Somatic Nervous System: A part of the PNS that controls voluntary movements of skeletal muscles.
Blood vessels, specifically capillaries, connect the small branches of arteries (arterioles) to the small branches of veins (venules), facilitating the exchange of oxygen, nutrients, and waste products between blood and body tissues.
Here's a more detailed explanation:
- Arteries:
  Carry oxygen-rich blood away from the heart to the body's tissues and organs.
- Veins:
  Carry deoxygenated blood back to the heart from the body's tissues and organs.
- Capillaries:
  Tiny blood vessels that connect the arteries and veins, allowing for the exchange of gases and nutrients between the blood and the surrounding tissues.
- Arterioles:
  Small arteries that branch off from larger arteries and connect to capillaries.
- Venules:
  Small veins that drain blood from capillaries and connect to larger veins.

- The tibia is the larger of the two bones in the lower leg.
- It is located on the inside of the lower leg, closer to the midline of the body.
- It connects to the knee joint at its top (proximal) end and the ankle joint at its lower (distal) end.
- The tibia is a weight-bearing bone, meaning it supports a significant portion of the body's weight when standing and moving.
- The fibula is the smaller, thinner bone located on the outside of the lower leg.
- It runs alongside the tibia but does not bear as much weight as the tibia.
- The top end of the fibula is located below the knee joint but is not part of the joint itself.
- The lower end of the fibula forms the outer part of the ankle joint.
- The fibula helps to stabilize the ankle and lower leg muscles.

The posterior talofibular ligament is a ligament that connects the fibula to the talus bone. It runs almost horizontally from the malleolar fossa of the lateral malleolus of the fibula to the lateral tubercle on the posterior surface of the talus.
The anterior talofibular ligament (ATFL) is the most commonly injured ligament in the ankle, often injured during inversion ankle sprains, especially when combined with plantar flexion.
Here's a more detailed explanation:
Why the ATFL is so prone to injury:
- Location and Function:
  The ATFL connects the anterior part of the talus (ankle bone) to the fibula (lower leg bone) and plays a crucial role in stabilizing the lateral (outer) side of the ankle joint, preventing excessive inward movement (inversion) and anterior displacement of the talus.
- Mechanism of Injury:
  Ankle sprains, particularly those involving forced inversion (rolling the ankle inward) and plantar flexion (pointing the toes down), put the ATFL under significant stress and can lead to tears or sprains.
- Weakness:
  The ATFL is considered the weakest of the three lateral ligaments (ATFL, calcaneofibular ligament (CFL), and posterior talofibular ligament (PTFL)), making it more susceptible to injury.
- Common Occurrence:
  Studies show that ATFL injuries are involved in a large percentage of ankle sprains, with some research suggesting that up to 85% of ankle sprains involve the ATFL.
Symptoms of an ATFL injury:
- Pain on the outside of the ankle
- Swelling and bruising
- Tenderness to touch
- Instability or difficulty bearing weight
- Occasionally, a popping sensation at the time of injury
Grading of ATFL injuries:
- Grade 1:
  Mild sprain with minimal swelling and tenderness, little to no instability, and ability to walk with little pain.
- Grade 2:
  Moderate sprain with a broader area of tenderness, painful gait or inability to walk, bruising, and swelling.
- Grade 3:
  Severe sprain with complete rupture of the ATFL, diffuse swelling, inability to walk, and tenderness on both the lateral and medial aspects of the ankle.
Diagnosis and Treatment:
- A physical examination and a medical history can help diagnose an ATFL injury.
- Anterior drawer test can suggest injury to the ATFL and CFL.
- X-rays can help rule out fractures.
- MRI may be used to assess the extent of the injury.
- Treatment typically involves rest, ice, compression, and elevation (RICE), and may include immobilization, physical therapy, and in some cases, surgery.
The calcaneofibular ligament (CFL) is the second most commonly injured ligament in lateral ankle sprains, after the anterior talofibular ligament (ATFL), and is often injured in conjunction with the ATFL.
Here's a more detailed explanation:
- Lateral Ankle Ligaments:
  The lateral ankle ligaments, including the ATFL, CFL, and posterior talofibular ligament (PTFL), are crucial for ankle stability.
- Mechanism of Injury:
  Lateral ankle sprains, which often involve the ATFL and CFL, occur when the foot is forcefully inverted (rolled inward) and plantarflexed (pointed downward).
- CFL Injury:
  The CFL is a key stabilizer of the subtalar joint, and its injury can lead to instability and pain on the lateral side of the ankle.
- Isolated CFL Injury:
  While combined ATFL and CFL injuries are common, isolated CFL injuries are relatively rare.
- Treatment:
  Treatment for CFL injuries typically involves conservative measures like rest, ice, compression, and elevation (RICE), followed by rehabilitation to restore strength, proprioception, and function. In some cases, surgery may be necessary.
The calcaneus, commonly known as the heel bone, plays several crucial functions in the foot and ankle.
Weight Distribution:
- The calcaneus acts as a foundation for the foot, supporting and distributing the body's weight from the leg to the ground.
Leverage for Muscles:
- The calcaneus provides a lever arm for calf muscles, such as the gastrocnemius and soleus, to generate force for plantarflexion (pointing the toes).
Ankle Joint Stability:
- The calcaneus forms part of the ankle joint (subtalar joint). Its articulation with the talus bone allows for inversion and eversion movements of the foot.
Attachment for Tendons and Ligaments:
- The calcaneus serves as an attachment point for various tendons and ligaments, including the Achilles tendon, plantar fascia, and peroneal tendons. These structures help stabilize the foot and ankle.
Shock Absorption:
- The calcaneus's spongy bone structure helps absorb impact forces during activities such as walking, running, and jumping.
Overall, the calcaneus is an essential bone for maintaining foot and ankle function, weight distribution, and movement.

Referred pain on neck

c2-c3 = occipital/temporal
c4-c6 = neck
c5-c6 = gb21 (shoulder)
c6-c7 = medial side of scapula & t1

The trapezius muscle is a large, triangular-shaped muscle located in the upper back and neck. It extends from the base of the skull to the mid-back and covers the shoulders.
Anatomy
- The trapezius muscle is divided into three parts:
  - Upper trapezius (descending fibers)
  - Middle trapezius (transverse fibers)
  - Lower trapezius (ascending fibers)
- It originates from the occipital bone, ligamentum nuchae, and spinous processes of the seventh cervical (C7) to twelfth thoracic (T12) vertebrae.
- It inserts into the spine of the scapula, clavicle, and acromion process.
Function
The trapezius muscle plays a crucial role in:
- Elevating, depressing, and retracting the scapula (shoulder blade)
- Rotating the scapula upwardly
- Stabilizing the shoulder joint
- Supporting the head and neck
- Assisting in breathing
Common Conditions
- Trapezius strain: Overuse or injury can lead to pain, stiffness, and weakness in the upper back and shoulders.
- Trigger points: Tender knots within the trapezius muscle that can cause referred pain to other areas, such as the neck, head, and arms.
- Myofascial pain syndrome: Chronic pain in the trapezius muscle and surrounding tissues.
The sternocleidomastoid muscle (SCM), also known as the "neck muscle", is located on the front of your neck, running from the sternum (breastbone) and clavicle (collarbone) to the mastoid process behind your ears. It's a paired muscle that helps with head rotation and flexion, and can cause pain or discomfort if strained or tight.
Here's a more detailed breakdown:
- Location and Function:
  - The SCM is a prominent muscle on the front of the neck, running from the sternum and clavicle up to the mastoid process behind the ears.
  - It's a paired muscle, meaning there's one on each side of the neck.
  - It plays a crucial role in head movement, allowing you to rotate and flex your head.
  - It also helps with breathing by assisting in elevating the rib cage.
- Anatomy:
  - "Sterno" refers to the sternum (breastbone).
  - "Cleido" refers to the clavicle (collarbone).
  - "Mastoid" refers to the mastoid process, a bony projection behind the ear where the muscle attaches.
- Causes of Pain or Discomfort:
  - Strain: The SCM muscle can become strained or injured, especially from repetitive movements, poor posture, or trauma.
  - Tightness: Prolonged poor posture or stress can lead to tightness in the SCM muscle.
  - Muscle Spasms: Muscle spasms in the SCM can cause pain and stiffness.
  - Trigger Points: Myofascial trigger points in the SCM can cause referred pain in the neck, head, and even the ear.
- Symptoms of SCM Pain:
  - Pain in the neck, shoulders, or behind the ear.
  - Difficulty holding up your head.
  - Headaches or migraines.
  - Dizziness or imbalance.
  - Pain in the jaw, cheek, or ear.
The levator scapulae muscle, located in the neck and upper back, is a key muscle for elevating the shoulder blade and tilting the head, and its name means "elevator of the scapula".
Here's a more detailed explanation:
- Location: The levator scapulae muscle is located on the side of the neck and upper back, specifically in the posterior triangle of the neck.
- Function:
  - Elevation of the Scapula: Its primary function is to elevate the shoulder blade (scapula).
  - Tilting the Head: It also helps in tilting the head from side to side.
  - Neck and Shoulder Stability: It plays a role in stabilizing the shoulder area during arm movements.
- Origin and Insertion:
  - Origin: The muscle originates from the transverse processes of the first four cervical vertebrae (C1-C4).
  - Insertion: It inserts onto the medial border of the scapula, between the superior angle and the junction of the spine of the scapula.
- Innervation: The muscle is innervated by the dorsal scapular nerve.
- Blood Supply: The levator scapulae muscle is supplied by the dorsal scapular artery.
- Clinical Significance:
  - Levator Scapulae Syndrome: This condition is characterized by pain and tenderness in the upper medial angle of the scapula, often exacerbated by movements that stretch the muscle.
  - Trigger Points: Trigger points in the levator scapulae muscle can cause pain that radiates to the shoulder and along the medial aspect of the shoulder blade.
  - Pain and Stiffness: Strains or irritation of the levator scapulae can cause pain, stiffness, and tightness in the upper back, neck, and shoulders.
  - Causes: Poor posture, prolonged sitting, and injuries can contribute to levator scapulae pain.
  - Treatment: Treatment options include physical therapy, massage, stretching, and addressing underlying causes like poor posture.

intervertebral disk herniation

radiculopathy: one side herniation
myelopathy: both sides herniated

10 types of lumbago due to:

Kd def = endless pain
Phlegm = edema fluid retention pain
Retention of undigested food = difficulty bending and stretching body
Strain and contusion = lifts heavy objects, works excessively, falls from high place
Blood stasis = pain recedes in day and worse at night
Wind = pain moves around left to right
Cold = pain recedes when meets warmth and worse with cold
Dampness = waist feels heavy
Damp heat = eats greasy food and is worse with cloudy weather
Qi = cannot stand for a long time and cannot walk for a long time