Human Musculoskeletal System and Sports Physiology Fundamentals

Musculoskeletal System Fundamentals

Mnemonic Rule for Muscle Regions

Neumotecnica Rule: A system for classifying muscle groups based on location and primary action:

• Superior Region:
  • Anterior: Flexors
  • Posterior: Extensors
• Inferior Region:
  • Anterior: Flexors
  • Posterior: Extensors

Lower Limb Musculature

Knee Muscles

Quadriceps Femoris (Extensors):

1. Rectus Femoris (Straight)
2. Vastus Lateralis
3. Vastus Medialis (Vast Interior)
4. Vastus Intermedius (Crural)

Hamstrings (Flexors): Biceps Femoris, Semitendinosus, and Semimembranosus.

Ankle and Foot Muscles: Actions and Primary Movers

1. Plantar Flexion (Foot Away):
   • Gastrocnemius (External and Internal Twin)
   • Soleus
2. Dorsiflexion (Foot Up):
   • Tibialis Anterior
   • Fibularis (Peroneus) Tertius
   • Extensor Digitorum Longus
   • Extensor Hallucis Longus
3. Eversion (External Rotation):
   • Peroneus Longus
   • Peroneus Brevis (Short)
4. Inversion (Internal Rotation):
   • Tibialis Posterior
   • Flexor Digitorum Longus
   • Flexor Hallucis Longus (Own)

Trunk and Neck Musculature

Neck Muscles

1. Flexion: Sternocleidomastoid
2. Extension: Trapezius (Upper Fibers) and other posterior neck muscles.

Trunk Muscles

1. Flexion: Rectus Abdominis, External Oblique, and Internal Oblique.
2. Extension: All muscles of the lumbar region (Erector Spinae group).
3. Rotation (Internal or External): External Oblique and Internal Oblique.

Hip Movement

1. Flexion: Iliopsoas and Sartorius.
2. Extension: Gluteus Maximus and Hamstrings.
3. Abduction: Gluteus Medius and Gluteus Minimus.
4. Adduction: Adductor Magnus, Adductor Longus (Medius), Adductor Brevis (Minimus), and Gracilis.
5. External Rotation: Pelvitrochanteric group (e.g., Piriformis).
6. Internal Rotation: Gluteus Minimus and Gluteus Medius.

Ankle Movement Summary

1. Plantar Flexion (Foot Away): Gastrocnemius (Internal/External Twin) and Soleus.
2. Dorsiflexion (Foot On): Tibialis Anterior, Anterior Peroneal (Fibularis), Extensor Digitorum, Extensor Hallucis Longus.

Muscle Fiber Types

Muscle fibers are categorized based on their metabolic and contractile properties:

Type I Fibers (Slow Twitch, Red)

• They are red because they have high concentrations of Myoglobin, which is responsible for carrying oxygen to the muscle.
• Contractions are slow.
• Do not fatigue easily (high endurance).
• Examples: Diaphragm, extensor muscles (postural).
• Perform endurance activities; contractions are less intense.
• Energy system: Aerobic (Oxygen) system.

Type II Fibers (Fast Twitch, White)

• They are white because Myoglobin levels are low.
• Contractions are fast.
• Fatigue easily.
• Examples: Flexors, muscles used for speed.
• Contractions are intense but last only a few seconds.
• Energy system: Anaerobic system.

Sports Physiology and Biomechanics

Beverage Intake and Hydration Guidelines

Before Activity: It is best to drink 0.5 liters (500 ml) two hours before exercise.

During Activity: Drink before you feel thirsty, approximately 200–250 ml every 15 or 20 minutes.

After Activity: Replace the same volume lost, often measured by weight loss.

Daily Water Balance (Approximate Liters)

Water Loss:

• Urine: 1.5 L
• Sweat: 0.5 L
• Ventilation (Respiration): 0.4 L
• Feces: 0.2 L
• Total Loss: 2.6 L

Water Intake:

• External Intake (Beverages): 1.3 L (Water and other drinks)
• Meals: 1.0 L
• Internal Intake (Metabolic Water): 0.3 L
• Total Intake: 2.6 L

Cardiovascular Response

The main function of the cardiovascular system during physical activity is to supply oxygen (O2) to active muscles and facilitate the removal of carbon dioxide (CO2).

Sports Biomechanics

Biomechanics is the study of the mechanical laws relating to the movement or structure of living organisms.

• Mechanical Kinematics: Describes motion without considering the forces causing it.
• Dynamics: Study of forces and their effects on motion.
  • Statics (Study of forces in equilibrium)
  • Kinetics (Study of forces causing motion)