Skeletal Most common Attached to bone (via tendons) Voluntary Striated
Cardiac Muscle In the heart only Involuntary Striated Smooth Muscle Surrounds organs Slow, long contractions Involuntary Non-striated; forms dense sheets
Complex linking of the muscular and neurological systems Constant use and practice improves the quality, efficiency and ability of these systems to work together E.g. agility training
Nerves transmit impulses in waves - the resulting contraction is called a muscle twitch 1 nerve + the muscle fibers it innervates = motor unit 1 nerve stimulates many muscle fibers, thereby producing muscle movements. 1 nerve + a few muscle fibers =fine movements (eg blinking) 1 nerve + lots of fibers = gross/big movements (eg contraction of the quadriceps) All-or-None Principle When a motor unit is stimulated to contract, either ALL of the muscle fibers will contract, or none will
Concentric Muscle fibers shorten E.g. bicep flexion Eccentric Muscle fibers lengthen Eg bicep extension Isometric Contraction without change in length of muscle; no motion; decreased risk of injury E.g. pushing against a wall; doing a abdominal plank.
Origin where the muscle attaches to more stationary of the bones of skeleton. Usually more superior Insertion Where the muscle attaches to the bone that moves most Usually more inferior
Skeletal muscles are arranged as opposing pairs Agonist Prime mover of the body part Eg. During knee extension, quadriceps are the agonist Antagonist Counter-acts the agonist Eg. During knee extension, hamstrings are the antagonist
Leg- refers to lower limb below the knee Thigh = hip to knee
Muscle/Musc le Group OriginInsertionAction Toe/foot extensors Anterior tibia/fibula Distal phalanges (toes) Extend the toes Tibialis Anterior Ant. TibiaTop of footDorsiflexion of ankle; foot inversion Gastrocnemi us Lateral and medial heads both originate on femur Achilles tendon, which inserts on the heel (calcaneus) Plantar flexes ankle; flexes knee SoleusUpper fibulaTendon combines with gastroc to form achilles heel. Plantar flexes ankle Flexor hallicus longus Posterior fibulaEnd of big toe (ie the distal aspect) Flexes big toe PeronealsFibula1 st and 5 th metatarsals Plantar flexion; eversion
Muscle/ Muscle Group OriginInsertionActionLocation Quadriceps femoris Iliac spine (pelvis) & proximal femur Come together as patellar tendon, insert on tibia Knee extension and hip flexion HamstringsPelvisHead of fibula and tibia Hip extension; knee flexion; internal knee rotation Gluteus maximus Pelvis and lower spine (iliac crest, sacrum, coccyx) Proximal femur (greater trochanter) and iliotibial tract ( IT band) Hip extension, external rotation Gluteus medius & minimus Lateral pelvisGreater trochanter/ femur Abduction; internal hip rotation Hip adductorsDistal pelvisAlong the femur Hip/ thigh adduction
Groups: Figure out where each muscle is located- ie anterior, posterior, medial, lateral Questions: While out trail running, Marie steps on a root and experiences an eversion of her ankle. a) What is this injury? (what happens to the sole of the foot) b) Which muscles will be injured? c) Which muscles would have contracted to aid ankle eversion? Many athletes, especially women, have muscular imbalances between their quadriceps and hamstring muscle groups(quads are often stronger). a) Why are these athletes at a higher risk for injury? b) What joint is most likely to be injured? c) What type of injury might result at this joint? The gluteus maximus is one of the strongest muscles in the body. a) What would happen to hip/thigh rotation if other muscles do not compensate for this strength? b) Which muscles are the antagonists to hip extension by the glutius maximus?
Muscle/GroupOriginInsertionActionLocation Rectus AbdominusPubic crestXyphoid process and inferior ribs Flex trunk; expiration; “bearing down” External Obliques AND Transverse abdominis Lower 8 ribsPelvisFlex and rotate vertebrae; compress abdomen during expiration Quadratus LumborumPelvis and lumbar vert. Lower rib and upper lumbar vert. Extends and bends vert. column; helps with breathing Erector Spinae DiaphragmSternum, ribs, lumbar vert. Central tendonRespiration; anatomical border, separating thoracic and abdominal cavities IntercostalsInferior of each ribSuperior of each rib respirationLayers of muscle b/w each rib
Jeff sustained a serious injury to the left side of his trunk. What muscle group(s) are affected? What movements will be compromised? What could happen if the diaphragm was punctured or torn in half? A pregnant woman is in a car accident and sustains an injury to her rectus abdominus (baby is fine). What might be the consequences?
Muscle/groupOriginInsertionActionLocation Latissimus dorsi Sacrum, lumbar, thoracic vert HumerusAdduction, extension, interior rotation of arm Pectoralis majorClavicle, sternum, external obliques HumerusAdduction, flexion, internal rotation of arm Rotator Cuff (4 muscles) ScapulaHumerusShoulder stabilization and rotation TrapeziusBase of occipital bone (head); cervical and thoracic vert. Scapula and shoulder bone bones (acromion, clavicle) Moves the scapula; extends the neck Deltoids (anterior, lateral, posterior) Clavicle, acromion, scapula HumerusFlexion, extension, abduction and rotation of arm
Muscle/Grou p OriginInsertionActionLocation Biceps brachiii 2 places on the scapula RadiusElbow flexion; forearm supination Triceps brachii 3 heads on posterior humerus Ulna (olecranon- point of elbow) Elbow extension Hand FlexorsElbow areaHand/fingersFlex wrist, hand, fingers Hand Extensors Elbow areaHand/fingersExtend wrist, hand, fingers
Types: Fibrous joints – no movement- eg sutures of the skull Cartilaginous joints- some movement- eg between the vertebrae Synovial joints- lots of movement 6 common types: Ball and socket (eg the hip, shoulder) Gliding (eg foot) Hinge (elbow, knee) Pivot (neck) Saddle (thumb) Ellipsoid (wrist)
Separated by a lubricating fluid and cartilage Joined by ligaments that also help form the joint capsule (surrounds and protects joint)
http://www.youtube.com/watch?v=9QTCBrefXso http://www.youtube.com/watch?v=9QTCBrefXso Tendinitis Inflammation of a tendon via irritation due to overuse/abnormal use Tx- rest, cold, heat therapy, anti-inflammatories Tears, Sprains, Pulls Tear/pull= injury to muscle Sprain = injury to ligaments and tendons 3 levels of severity: 1 st degree injury is mild; 2 nd is moderate; 3 rd is severe Dislocations When bone displaced from original position Symptoms: Joint looks awkward/deformed Painful to touch/move Inability to use joint
Recognizing an Injury SHARP Swelling Heat Altered function Red Pain Treating RICE Rest Ice Compression Elevation NEVER use heat to initially treat an injury Why?
strengthen surrounding muscles Stretch muscles Proper conditioning Warm up before exercising Proprioceptive training
Muscles Causing Movement at the Hip Joint Iliopsoas Adductor Muscles Gluteus Maximus Gluteus Medius Muscles Causing Movement at the Knee Joint Sartorius Quadriceps Group Rectus Femoris Vastus Muscles Hamstring Group Biceps Femoris Semimembranosus Semitendinosus Muscles Causing Movement at the Ankle and Foot Tibialis Anterior Peroneus Muscles Gastrocnemius