Ch. 3 Muscular Anatomy - PHED 225

Joint Actions

When muscles contract, the subsequent joint movements can be described based on how the joints reorient with shorter muscles. Each isotonic muscular contraction produces some level of movement, which when described, helps define each strength training exercise. These movements specifically occur in each of the cardinal planes of movement.

Flexion

When the joint angle decreases with a bending motion

Adduction

a movement toward the midline EX: iron cross in gymnasts *Add TOGETHER= arms are added to the body together

Which of the following movements best describes the hips during a deadlift a. Rotation b. Extension c. Abduction

b. Extension

Which plane of motion is the best choice to describe the hip movement during a deadlift? a. Transverse b. Sagittal c. Frontal

b. Sagittal

gluteus maximus

butt, which contributes to hip extension and is critical to movements like the deadlift and the squat.

Extension

is a straightening movement where the joint angle increases

Latissumus Dorsi

A large muscle of the middle and lower back. The primary contribution of the so-called lats is adduction of the arms. The lats are heavily recruited when doing pull-ups.

Trapezius

A large, kite-shaped muscle extending from the skull most of the way down the back. The trapezius has a variety of movements including neck extension and rotation, shoulder elevation, and a lot of other movements associated with the shoulder blades. People participating in strength training will use the traps most commonly when doing shrugs.

Quadriceps

A muscle group with four different muscles, primarily responsible for knee extension. The rectus femoris, vastus medialis, vastus lateralis, and nestled beneath the rectus femoris is the vastus intermedius. Each of the quad muscles is integral to knee extension activities, such as squatting.

Tensor Fasciae Latae (TFL)

A very small muscle on the outside of the hip. The TFL helps with hip abduction, but the importance of this muscle is the connective tissue band (the iliotibial or IT band) that runs from the muscle all the way down the side of the leg to the knee. The reason for including such a small and seemingly inconsequential muscle is that it is a prime location for overuse injuries, especially among runners, or people changing their activity habits. Therefore, it is important to be attentive to the status of this muscle and the associated connective tissue band to help avoid potential injury.

Obliques

Both internal and external--wrap around the sides of the body and provide rotational forces. In addition to providing core strength and stability, these muscles are often trained by rotational athletes like lacrosse, tennis, and baseball players.

Frontal (or Coronal) Plane

Divides the body back and front. EX: Movements towards the side, like dumbbell lateral raises, occur in the frontal plane.

Transverse Plane

Divides the body into upper and lower portions. EX: Twisting movements, like Russian Twists, occur in the transverse plane

Sagittal Plane

Divides the body left and right. EX: Movements in the forward and backward directions occur in this plane. For example, running is characterized by a great deal of movement in the sagittal plane.

Satorius

Flexes the leg and thigh, abducts the thigh, rotates the thigh laterally, and rotates the leg medially. The "tailor's muscle" because it helps pull the leg into a cross-legged position, similar to the way a tailor used to sit when working. The sartorius is not commonly isolated in strength training, but it is integral in stabilizing during different leg exercises.

Upper Body Muscles

Latissumus Dorsi, Trapezius, Triceps Brachii, Biceps Brachii, Deltoids, Pectoralis Major

Triceps Brachii

Located on the back of the arm, directly opposite of the biceps brachii. These muscles are integral to elbow and shoulder extension. Commonly, the triceps are associated with isolation exercises like pulldowns, but elbow extension is also required in compound movements like bench and military presses.

Hamstrings

Located on the back of the legs, and are responsible for knee flexion if the hips are stabilized, and also hip extension if the hip is not stabilized. The three muscles of the hamstrings include Biceps femoris, semitendinosus, and semimembranosus. The hamstrings can be worked using exercises like the deadlift.

Pectoralis Major

Primary muscle of the chest responsible for pushing and pressing movements. The most common exercise using this muscle group is the Bench Press.

Deltoids

Primary muscles of the shoulders. The deltoids are responsible for shoulder abduction, as well as shoulder flexion and extension. The military press and dumbbell flys are common exercises used to develop the deltoid

Biceps Brachii

Primary muscles on the front of the upper arm responsible for elbow flexion. The biceps work with brachialis, brachioradialis, and coracobrachialis to control the elbow and the shoulder, depending on the orientation of the wrist and how high the weight is lifted. The most common exercise associated with the biceps is a curl.

Lower Body Muscles

Quadriceps, Hamstrings, Gluteus Maximus, Calves/Tricep Surae, Sartorius, Adductors, Tensor Fasciae Latae

Core Muscles

Rectus Abdominus, Obliques

Rectus Abdominus

The proverbial "6-pack" abs. This muscle helps with trunk flexion, like when completing a sit-up. However, when isometrically contracted, the rectus abdominus also provides core stability for compound movements like squats and deadlifts.

Calves/Triceps Surae

This muscle group is composed of two muscles that have similar joint actions. Both muscles point the toe down (plantar flexion), but the gastrocnemius is more influential when the knee is extended, and the soleus is more influential with a flexed knee. Calf raises are an obvious example of a popular exercise to train the calves.

Adductors of thigh

Unique muscles of the inner thigh that adducts, flexes, and rotates thigh.

Frontal Plane Movements

abduction and adduction

sagittal plane movements

flexion and extension

Abduction

movement away from the midline EX: when an exerciser spread their feet wider than normal to stretch the inside of the leg. *Aliens Abduct you away from earth

Transverse Plane Movements include _________, which is a twisting motion. Think about a rotation like someone swiveling in an office chair or a baseball player swinging a bat.

rotation