Knowledge of the main bones of the skeletal system is necessary to understand why you can or can’t do certain asanas, because your skeletal system plays a main part in how you move. Muscles can be stretched, but bones will be bones.
The human body is made up of 206 bones. They are as strong as steal, if you use them in the right way and direction. Movement strengthens bones. No movement weakens them.
When we look at bones, we divide them in:
- Long bones: leverage
- Flat bones: protect
- Short bones: bare weight
The main bones of the upper body
- Ulna (medial)
- Radius (lateral)
- Carpals (8)
- Metacarpals (5)
- Phalanges (14)
The main bones of the lower limbs
- Femur (longest bone in the body)
- Tibia (medial)
- Fibula (lateral)
- Patella: in yoga we use the patella as a reference point for the alignment of our femur and tibia
- Tarsals (7): calcaneus (heel bone), talus (on top of calcaneus):articulates with the tibia
- Metatarsals (5)
- Phalanges (14)
Your upper arm has one single bone: the humerus. It runs from the scapula to your elbow, where it forms a connection with the bones of your lower arm: the radius and ulna. The olecranon of the ulna form your elbow. The distal end of the radius forms your wrist joint with your carpals.
Your hand consists of eight carpal bones, five metacarpal bones (palm of our hand), and five phalanges (fingers).
Shoulder / pectoral girlde
Your shoulder / pectoral girdle attach your limbs to the axial skeleton. The shoulder girdle consist of two scapulae and two clavicles. The clavicles are connected with the sternum. This is the only connection between the shoulder girdle and your axial skeleton. Both scapulae are supported and held in place by skeleton muscles. They are not connected to the thorax
The position of the clavicle (more turned forwards or backwards) determines how far the upper arm can be raised backwards, without moving the shoulder girdle. Moving the upper arm upwards and backwards is needed for back bends, like upward bow.
Your pelvic girdle is made up out of 3 bones that are ‘fused’ together: ilium, ischium (sit bones) and your pubic bone. Your pelvis girdle connects with your femurs (thighbones/femurs). Because your legs and pelvic girdle have to support the weight of your upper body these bones are stronger and bigger than the bones of your shoulder girdle. The upper edge of your pelvic girdle is the crista iliac (iliac crest); this is an important attachment place for a lot of muscles and ligaments.
Your pelvis protects your delicate organs of the abdominopelvic cavity (abdominal cavity and the pelvic cavity) while anchoring the powerful muscles of the hip, thigh, and abdomen. Several bones unite to form the pelvis, including the sacrum, coccyx (tail bone), and the left and right coxal (hip) bones.
Women tend to have a smoother and lighter pelvis than man. Their pelvis is wider and lower and the opening of the pelvis is bigger. The pelvis is constructed differently, because women have to be able to give birth. A lower and wider pelvis makes it easier to bend forward and to rotate legs outwards (lotus pose).
Femur, patella and tibia
The legs consist of the femur, patella, tibia and fibula. The femur is the longest and heaviest bone of your skeleton. The head of the femur (epiphysis) is connected to the pelvis with muscles and ligaments. On the outside of your hip, you can feel your trochanter major. The distal end of the femur is part of your knee joint.
The tibia is the biggest bone of your lower leg. It’s connected with the femur in the knee joint. The thinner fibula is connected with the tibia at the far end (lateral) of our leg. There is no connection between the fibula and the femur.
Your feet consists of seven tarsal bones, five metatarsal bones (their distal edges form the balls of your feet) and five phalanges (your toes). The look a lot like your hands
The way your bones are connected together in your joints and the space one bone has with reference to another determines which yoga poses come easily for a yogi and which are undo-able. We will take a closer look at this when we talk about joints.