Comprehensive Notes on Kinesiology, Musculature, and Movement Analysis

Planes of Motion, Axes of Rotation, and Joint Actions

  • Relationship Between Planes and Axes:

    • Axes of rotation run perpendicular to their corresponding plane of motion.
    • Sagittal Axis: Runs front to back. Pairs with the Frontal Plane of motion.
    • Frontal Axis: Runs right to left. Pairs with the Sagittal Plane of motion.
    • Vertical Axis: Runs top to bottom straight down through the body. Pairs with the Transverse Plane of motion.

  • Transverse Plane Movements:

    • Hypertrophic / hypertoid motions occurring transversely include twisting, supination, pronation, and axial rotation.

  • Joint Actions & Directional Movements:

    • Shoulder Extension: Backward movement of the shoulder joint in the sagittal plane.
    • Shoulder Flexion: Forward/upward movement of the shoulder joint in the sagittal plane.
    • Shoulder External Rotation: Lateral movement of the shoulder joint away from the midline in the transverse plane.
    • Shoulder Abduction: Lateral movement of the arm away from the midline of the body in the frontal plane.
    • Hip Internal Rotation: Medial rotation of the hip causing the knee to turn inward.
    • Elbow Supination: Rotation of the forearm placing the palm upward/anteriorly.
    • Elbow Pronation: Rotation of the forearm placing the palm downward/posteriorly.
    • Ankle Plantar Flexion: Extension of the ankle pointing the foot/toes downward away from the shin.
    • Trunk Lateral Flexion: Side-bending movement of the spine in the frontal plane.
    • Trunk Reduction: Movement returning the spine back to anatomical position from a position of lateral flexion.

Principles of Muscle Function and Contraction Types

  • Anatomical Muscle Locations Relative to Anatomical Position:

    • Anterior Muscles: Located on the front aspect of the body relative to anatomical position. Innervate movements that bring the body forward.
    • Posterior Muscles: Located on the back aspect of the body relative to anatomical position. Innervate movements that bring the body posterior (to the back).
    • Lateral Muscles: Located on the side aspects of the body relative to anatomical position. Innervate movements that bring the body laterally.

  • Functional Roles of Muscles:

    • Agonist (Prime Mover): The muscle responsible for innervating and producing the muscle action taking place.
    • Antagonist: The opposite muscle that lengthens to allow movement to occur. Agonists and antagonists form opposite pairs performing opposite joint motions and muscle actions.

  • Types of Muscle Actions:

    • Concentric Phase: Dynamic contraction involving shortening of the agonist muscle during the working or hardest phase of movement.
    • Eccentric Phase: Dynamic contraction involving lengthening of the agonist muscle back down. Represents the easier or controlled phase of movement.
    • Isometric Phase: Muscle contraction where force is produced with no change in muscle length and no movement across phases (e.g., holding a static plank position).

  • Functional Examples of Agonist-Antagonist Mechanics:

    • Shoulder Flexion vs. Extension:
      • During shoulder flexion, pectoralis muscles act as agonists (contracting and shortening), while latissimus dorsi muscles lengthen.
      • During shoulder extension, latissimus dorsi muscles act as agonists (shortening), while pectoralis muscles lengthen.
    • Bicep Curl (Elbow Flexion & Extension):
      • Elbow Flexion (Concentric Phase): Biceps brachii acts as the agonist (shortening), triceps brachii acts as the antagonist (lengthening).
      • Elbow Extension (Eccentric Phase): Biceps brachii actively lengthens while lower phase occurs.
    • Spinal Movements:
      • Trunk Flexion: Rectus abdominis acts as the agonist (fully contracting/shortening), while erector spinae (long muscle running from base of neck to tailbone) acts as the antagonist (fully lengthening).
      • Trunk Extension: Erector spinae contracts/shortens as agonist, while rectus abdominis fully lengthens as antagonist.
    • Hamstring Curl:
      • Concentric Phase (Knee Flexion): Hamstrings act as agonist (shortening), quadriceps act as antagonist (lengthening).
      • Eccentric Phase: Hamstrings lengthen as knee extends back down.

Primary Musculature, Anatomical Locations, and Palpation Procedures

  • Laboratory Safety and Palpation Guidelines:

    • Explicit and specific verbal consent must always be requested prior to touching or palpating partners (e.g., asking "Is it okay if I touch you?").
    • Tactile feel and muscle contraction visibility are optimized by having partners perform isometric resistance or active joint movements.
    • Tape labels applied directly over muscle bellies illustrate contraction mechanics: tape scrunches/folds during concentric shortening and stretches during eccentric lengthening.

  • Upper Body & Trunk Musculature:

    • Deltoid (Delt):
      • Location: Lateral aspect of the body on the shoulder.
      • Primary Muscle Action: Shoulder abduction.
      • Secondary Actions: Shoulder flexion, shoulder extension, horizontal adduction.
      • Palpation Method: Have partner abduct shoulder at a 90∘90^\circ angle to reveal and feel the triangular V-shaped muscle pop out laterally.
    • Pectoralis Major / Minor (Pecs):
      • Location: Anterior aspect of the upper chest spanning across the torso.
      • Primary Muscle Action: Shoulder flexion.
      • Secondary Actions: Horizontal adduction, shoulder internal rotation.
      • Palpation Method: Resist horizontal adduction with arms flexed at a 90∘90^\circ angle to feel muscle belly contraction across the chest.
    • Latissimus Dorsi (Lats):
      • Location: Posterior aspect of the body, extending from the scapula down to the lower back.
      • Primary Muscle Action: Shoulder extension.
      • Secondary Actions: Shoulder adduction, shoulder internal rotation.
      • Palpation Method: Have partner perform a mini "lat spread" or place hands behind back and push elbows forward to feel contraction in the mid-to-lower back.
    • Biceps Brachii (Biceps):
      • Location: Anterior upper arm, extending from lower shoulder to crease of elbow.
      • Primary Muscle Action: Elbow flexion.
      • Secondary Actions: Elbow supination, shoulder flexion.
      • Palpation Method: Have partner perform elbow flexion (bicep curl motion).
    • Triceps Brachii (Triceps):
      • Location: Posterior upper arm.
      • Primary Muscle Action: Elbow extension.
      • Secondary Actions: Shoulder extension.
      • Palpation Method: Have partner perform resisted elbow extension or shoulder extension backwards.
    • Wrist Flexor Group:
      • Location: Anterior aspect of the forearm.
      • Primary Muscle Action: Wrist flexion.
      • Secondary Actions: Wrist abduction, wrist adduction, finger flexion.
      • Palpation Method: Have partner curl wrist and fingers upward/forward to feel muscle group activate across anterior forearm.
    • Wrist Extensor Group:
      • Location: Posterior aspect of the forearm.
      • Primary Muscle Action: Wrist extension.
      • Secondary Actions: Wrist abduction, wrist adduction, finger extension.
      • Palpation Method: Have partner extend wrist and fingers backward to feel tendons and muscle bellies move across posterior forearm.
    • Erector Spinae:
      • Location: Posterior aspect running bilateral columns from base of neck down to tailbone/sacrum.
      • Primary Muscle Action: Trunk / vertebral extension.
      • Secondary Actions: Lateral flexion.
      • Palpation Method: Have partner extend back backward to feel two parallel muscle columns pop out in lower and upper back.
    • Rectus Abdominis:
      • Location: Anterior aspect of abdomen running vertically on left and right sides.
      • Primary Muscle Action: Trunk / vertebral flexion.
      • Secondary Actions: Posterior pelvic tilt.
      • Palpation Method: Have partner brace core or perform posterior pelvic tilt (tucking hips in).

  • Lower Body Musculature:

    • Gluteus Maximus (Glute Max):
      • Location: Posterior hip and pelvic region.
      • Primary Muscle Action: Hip extension.
      • Secondary Actions: Hip external rotation, hip abduction, hip adduction.
      • Palpation Method: Have partner extend leg backward to feel glute contraction. Tape can be placed over glute belly or lower back superior to glute.
    • Iliopsoas Group:
      • Location: Deep anterior hip connecting femur to spine and anterior superior iliac spine (ASIS).
      • Primary Muscle Action: Hip flexion.
      • Secondary Actions: Anterior pelvic tilt, minor core stabilization.
      • Palpation Method: Have partner lift leg up into hip flexion; feel contraction at anterior hip crease.
    • Quadriceps Group (Quads):
      • Location: Anterior thigh (composed of four distinct muscles).
      • Primary Muscle Action: Knee extension.
      • Palpation Method: Have partner perform knee extension while seated to isolate quad contraction.
    • Hamstrings Group:
      • Location: Posterior thigh (composed of major distinct muscles).
      • Primary Muscle Action: Knee flexion (and hip extension).
      • Palpation Method: Have partner flex knee backward.
    • Calves (Gastrocnemius & Soleus):
      • Location: Posterior lower leg (composed of superficial gastrocnemius and deeper soleus).
      • Primary Muscle Action: Ankle plantar flexion.
      • Palpation Method: Have partner perform heel raise.
    • Tibialis Anterior:
      • Location: Anterior-lateral aspect of tibia.
      • Primary Muscle Action: Ankle dorsiflexion (and inversion).
      • Palpation Method: Have partner pull foot/toes upward toward shin.

Presentations & Biomechanical Movement Analyses

  • Biceps Brachii Presentation:

    • Location: Anterior upper arm.
    • Primary Joint Motion: Elbow flexion.
    • Everyday Motion: Grabbing or lifting a purse.
    • Plane of Motion: Sagittal plane.
    • Axis of Rotation: Frontal axis.
    • Agonist: Biceps brachii.
    • Antagonist: Triceps brachii.
    • Concentric Phase: Elbow flexion (lifting purse upward).
    • Eccentric Phase: Elbow extension (lowering purse back down).

  • Triceps Brachii Presentation:

    • Location: Posterior upper arm.
    • Primary Joint Motion: Elbow extension.
    • Everyday Motion: Pulling down blind cords to operate window blinds.
    • Plane of Motion: Sagittal plane.
    • Axis of Rotation: Frontal axis.
    • Agonist: Triceps brachii.
    • Antagonist: Biceps brachii.
    • Concentric Phase: Elbow extension (pulling down on cord).
    • Eccentric Phase: Elbow flexion (releasing cord upward under control).

  • Erector Spinae Presentation:

    • Location: Posterior trunk along vertebral column.
    • Primary Joint Motion: Trunk extension.
    • Everyday Motion: Stretching backward upon getting out of bed.
    • Plane of Motion: Sagittal plane.
    • Axis of Rotation: Frontal axis (Note: Transverse plane and vertical axis apply when twisting/rotational movement is included).
    • Agonist: Erector spinae.
    • Antagonist: Rectus abdominis.
    • Concentric Phase: Trunk extension (reaching/stretching backward).
    • Eccentric Phase: Returning forward into flexion.

  • Gluteus Maximus Presentation:

    • Location: Posterior hip / gluteal region.
    • Primary Joint Motion: Hip extension.
    • Everyday Motion: Standing up from a chair, walking, or ascending stairs.
    • Plane of Motion: Sagittal plane.
    • Axis of Rotation: Frontal axis.
    • Agonist: Gluteus maximus.
    • Antagonist: Iliopsoas.
    • Concentric Phase: Hip extension (standing up from seated position).
    • Eccentric Phase: Hip flexion (controlling body weight sitting back down into chair).

  • Core Rule of Concentric Phase Analysis:

    • The concentric phase occurs when the worked joint/muscle performs its primary motion in its hardest position against resistance.