PERSONAL FITNESS 10 Musculoskeletal System Notes HCS1050.
Transcript of PERSONAL FITNESS 10 Musculoskeletal System Notes HCS1050.
PERSONAL FITNESS 10
Musculoskeletal System Notes
HCS1050
Anatomical, Directional & Regional Terms
Skeletal System Functions
Support soft tissues & provide attachment sites for muscles
Movement at joints when muscles are contracted
Protects organs (e.g., skull encases brain)
Stores calcium, phosphorous, fat, sodium & other minerals
Production of blood cells
Bones
Continuously being remodeled via osteoclasts & osteoblasts Osteoclasts break down bone Osteoblasts build bone
“When bone is subjected to stress, more tissue is created (bone density increases)”
Joints of the body & Planes of Movement
Fibrous Joints
Cartilaginous Joints
Synovial Joints Joint movement occurs within 3 planes of
motion Sagittal Frontal Transverse
Sagittal Plane
Frontal Plane
Transverse Plane
Proprioception
The sense of knowing where the body is in relation to its various segments and the external environment. Receptors in the skin, in and around the
joints and muscles, and in the inner ear transmit the information
Types of Muscles
Skeletal Attaches to the skeleton via tendons, contracts to move
bones Voluntary Striated appearance
Smooth Found on walls of hollow organs (stomach, blood vessels) Involuntary & smooth
Cardiac Forms the walls of the heart Involuntary & smooth
Skeletal Muscle Fiber Types (Slow Twitch)
Slow-twitch muscle fibers Also called Oxidative or Type 1 muscle
fibers Contract more slowly Have lower force outputs More efficient More fatigue resistance
Fast Twitch Muscle Fibers
Two types of Fast-twitch muscle fibers Fast-oxidative glycolytic (Type IIa) fibers
Possess speed, fatigue and force production somewhere between Type I and Type IIx
For this reason, type IIa are also called intermediate fibers
Fast-glycolytic (Type IIx) fibers Limited capacity for aerobic metabolism Fatigue the fastest of the 3 types Considerable anaerobic capacity Largest and fastest Capable of producing the most force of all skeletal
muscle fiber types
Two Muscle Proteins & Connective Tissue
Actin Thin myofilament muscle protein
Myosin Thick myofilament muscle protein
Connective Tissue Tendons connect muscle to bone Ligaments connect bone to bone
Muscle Fiber Microanatomy
Skeletal muscle are made up of many muscle fibers
Muscle fibers are made up of myofibrils (protein filaments) composed of a series of repeating segments called sarcomeres
Sarcomeres, made up of thick (myosin) and thin (actin) myofilaments, are the functional contracting unit of skeletal muscle
Sliding Filament Theory of Muscle Contraction
Acetylcholine is released from the CNS Once detected, calcium is released
Calcium exposes binding sites along the actin for the myosin to attach to
Cross bridges are formed & the myosin pulls the actin toward the center thereby shortening the sarcomere and the muscle fiber itself
If multiple muscle fibers are stimulated to contract at the same time, the muscle will try to actively shorten by contracting
Sliding Filament Model
Sliding Filament Theory
Factors that Impact Flexibility Soft tissues contribute to the total resistance of
joints as follows (we can impact these by stretching): Joint capsule: 47% Muscle fascia: 41% Tendons: 10% Skin: 2%
Other factors that impact flexibility include (we can minimize these by working on flexibility): Age Gender Joint structure and past injury
Human SkeletonSkull
Mandible (Jaw)Clavicle (Collarbone)SternumHumorous
RibsVertebraePelvisRadiusUlnaCarpalsMetacarpalsPhalangesFemur
Patella (Kneecap)
TibiaFibula
TarsalsMetatarsalsPhalanges
Muscles of the Body
The Shoulder Girdle
Upper Trapezius
Middle Trapezius
Serratus Anterior
Lower Trapezius
Levator Scapulae
Rhomboid Minor
Rhomboid Major
Muscles that act at the Shoulder Girdle
The Rotator Cuff
Supraspinatus
Infraspinatus
Teres Minor
Glenohumeral joint
Greater Tubercle
Lesser Tubercle
Subscapularis
The Shoulder
Medial Deltoid
Anterior Deltoid
Pecs (Clavicular)
Pecs (Sternal)
Posterior Deltoid
Pectoralis MajorMiddle DeltoidLatissimus Dorsi
Posterior Deltoid
Anterior View Lateral View Posterior View
Muscles that act at the Shoulder
The Elbow
Anterior View Posterior View
Muscles that act at the Elbow
The Wrist
Muscles that act at the Wrist
The Trunk
External Abdominal Oblique
Internal Abdominal Oblique
Pectoralis Major
Rectus Abdominal
Transverse Abdominis
Tendinous Transcriptions
The Lower Back
Longissimus
Spinalis
Iliocostalis
Muscle that act on the Trunk
Hip Extensors
Semitendonosus
Semimembranosus
Biceps Femorus
Gluteus Maximus Gluteus
Medius
Illiotibial Band
Muscles that act at the Hip Joint
Hip Flexors and Quadriceps Group
Vastus Lateralis
Vastus Intermedialis
Vastus Medialis
Vastus Lateralis
RectusFemorus
Vastus Medialis
Muscles that act at the Hip Joint
Muscles that act at the Knee Joint
The Calves
Soleus
Achiles Tendon
Gastrocnemius
Muscles that act at the Ankle Joint
Four Types of Postural Alignment
Ideal Kyphosis Flat Back Sway Back