Muscles CRMA #4
What Are the Muscles and What Do They Do? • Bones don't work alone they need help from the muscles and joints. Muscles pull on the joints, allowing us to move. They also help the body perform other functions so we can grow and remain strong, such as chewing food and then moving it through the digestive system. • The human body has more than 650 muscles, which make up half of a person's body weight. They are connected to bones by tough, cord-like tissues called tendons, which allow the muscles to pull on bones. If you wiggle your fingers, you can see the tendons on the back of your hand move as they do their work.
Skeletal muscle is attached to bone, mostly in the legs, arms, abdomen, chest, neck, and face. Skeletal muscles are called striated (pronounced: stry-ay-ted) because they are made up of fibers that have horizontal stripes when viewed under a microscope. These muscles hold the skeleton together, give the body shape, and help it with everyday movements (they are known as voluntary muscles because you can control their movement). They can contract (shorten or tighten) quickly and powerfully, but they tire easily and have to rest between workouts. • Smooth, or involuntary, muscle is also made of fibers, but this type of muscle looks smooth, not striated. Generally, we can't consciously control our smooth muscles; rather, they're controlled by the nervous system automatically (which is why they are also called involuntary). Examples of smooth muscles are the walls of the stomach and intestines, which help break up food and move it through the digestive system. • Smooth muscle is also found in the walls of blood vessels, where it squeezes the stream of blood flowing through the vessels to help maintain blood pressure. Smooth muscles take longer to contract than skeletal muscles do, but they can stay contracted for a long time because they don't tire easily. • Cardiac (pronounced: kar-dee-ak) muscle is found in the heart. The walls of the heart's chambers are composed almost entirely of muscle fibers. Cardiac muscle is also an involuntary type of muscle. Its rhythmic, powerful contractions force blood out of the heart as it beats. Three Types of Muscles
Trapezius Daily uses Shrugging the shoulders Overhead movements or the arm
Location: Large muscle in upper and mid-back. • Function: Moves head sideways • Exercise to Strengthen it: upright rows, shoulder shrugs • Sample Stretch:Upper trap stretch. Sit in a chair, put your left hand behind you. Tilt your head so your right ear moves toward your right shoulder. Repeat on the other side. • Notes:Your upper trapezius connects your head to your shoulders. When you feel "knots in your neck", it's your trapezius.
Deltoids Daily uses Lifting
Location: Top of shoulder • Function: Overhead lifting • Exercise to Strengthen it: Push ups, bench press, side & rear arm raises • Sample Stretch: "Scratch your Back" - Put both hands over your head. Bend one elbow and place hand on back. With other hand, push elbow to stretch triceps, deltoids, lats • Notes: The deltoids are composed of three parts, anterior, posterior & medial. Anytime you "flap" your arms, your deltoids are working
Triceps Daily uses Pushing a door closed
Location: Back of upper arm • Function: Pushing • Exercise to Strengthen it: Push ups, triceps extensions, dips • Sample Stretch: "Scratch your Back" - Put both hands over your head. Bend one elbow and place hand on back. With other hand, push elbow to stretch triceps, deltoids, lats • Notes: Anytime you extend your lower arm, you are using your triceps
Pectoralis Daily uses Using roll-on deodorant
Location: Front of upper chest • Function: Push up from lying position, push open a door • Exercise to Strengthen it: push-up, pull-up, bench press • Sample Stretch: While standing, hold both arms out at shoulder height, palms forward. Pull arms back. • Notes: The pectoralis muscles pull the shoulder and arm forward.
1. You have all the muscle fiber you will ever have at birth. Once damaged they can’t be replaced. • 2. Arnold Schwarzenegger has as many muscle fibers as you – They’re just thicker! • 3. A single muscle cell of the Sartorius muscle in the thigh can be more than 12 inches long. • 4. There are more than 600 voluntary muscles in the body. • 5. The strongest muscle of the body is the masseter muscle used for chewing! • 6. Your hand contains 20 different muscles. • 7. If all your muscles could pull in one direction you could create a force of 25 tons! • 8. Muscles account for approximately 40% of your body weight. • 9. It takes 17 muscles in your face to smile, but it takes 43 muscles to frown. • 10. You take approximately 5 million steps per year using your leg muscles!
Biceps Daily uses Picking up a shopping bag
Location: Front of upper arm Function: Lifting, pulling Exercise to Strengthen it: Bicep Curls Sample Stretch: Sit on floor. Place hands behind you with fingers pointing away from your body. Walk your hips away from your hands Notes:Anytime you move your hand toward your shoulder, you are using your biceps.
LatissimusDorsi Daily uses Pushing on the arms of a chair when standing up
Location: Lats are the large triangular muscle in the mid-back. Rhomboids are between the shoulder blades Function:Postural alignment, pulling open a door Exercise to Strengthen it: Lats - pull ups, chin ups, lat pull downs Rhomboids - chin-ups & bent arm rows Sample Stretch: "Scratch your Back" - Put both hands over your head. Bend one elbow and place hand on back. With other hand, To stretch rhomboids, "hug yourself" Cross your hands in front of you, place both hands on your shoulder blades. Notes: Developed lats give your back a "V" shape, making your waist appear smaller.
ABDOMINAL Daily uses Maintaining good posture
Location: Stomach Function: Postural alignment, pulling open a door Exercise to Strengthen it: Crunches, leg raises, twisting crunches Sample Stretch: You typically don't stretch your abs. For most people, the abs are not strong enough, so you need to work on strengthening them rather than stretching them Notes: The rectus abdominus is the muscle that is visible. The transversusabdominus muscle, which stabilizes your back is underneath.
Lee's striking speed from three feet with his hands down by his side reached five hundredths of a second. • Lee could take in one arm a 75 lb barbell from a standing position with the barbell held flush against his chest and slowly stick his arms out locking them, holding the barbell there for several seconds • In a speed demonstration, Lee could snatch a dime off a person’s open palm before they could close it, and leave a penny behind. • Lee performed one-hand push-ups using only the thumb and index finger. • Lee performed 50 reps of one-arm chin-ups. • Lee would hold an elevated v-sit position for 30 minutes or longer Bruce Lee