Transcript Length-Tension Relationship

Length-Tension Relationship
Sit-ups
Muscles that produce flexion at the hip
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Iliopsoas (Iliacus and Psoas major)
Sartorius*
Rectus femoris*
Tensor fasciae latae*
Pectinius (assists)
• *These muscles are two-joint muscles, also
acting at the knee
Iliopsoas: Iliacus and Psoas Major
• Origin:
– Iliacus: Illium
– Psoas major: Lumbar
vertebrae and sacrum
• Insertion:
– Lesser trochanter of the
femur and just below
• Actions:
– Flexion at the hip
– External or lateral rotation at
the hip
Iliacus muscle
Psoas major
Sartorius
• Origin:
– Anterior superior iliac
spine
• Insertion:
– Anterior-medial aspect
of the tibia
• Actions:
– Flexion at the hip
– External (lateral) rotation
at the hip
– Flexion at the knee
Rectus Femoris
• Origin:
– Anterior inferior iliac
spine (ilium)
• Insertion:
– Patella, patellar tendon, tibial
tuberosity
• Actions:
– Flexion at the hip
– Extension at the knee
Rectus Femoris
Tensor fascia latae
• Origin:
– Iliac crest (Illium)
• Insertion:
– Iliotibial tract
• Actions:
– Flexion of the hip
– Abduction of the hip
– Slight internal rotation at
the hip
Tensor Fascia Latae
Muscles of the abdomen
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Rectus abdominis
External oblique
Internal oblique
Transverse abdominis
Rectus Abdominis:
• Origin: pubis (pubic crest,
symphysis pubis)
• Insertion: sternum and
ribs (xiphoid process,
cartilage)
• Actions:
– Both=flexion,
compression
– Single= lateral flexion
External Obliques:
• Origin: ribs (lower 8)
• Insertion: Iliac crest,
pubis, inguinal ligament,
linea alba
• Actions:
– Both: flexion
– Single: lateral flexion,
rotation
• External Oblique
• External oblique
Internal Obliques:
• Origin: Iliac crest,
inguinal ligament
• Insertion: ribs, linea alba
• Actions:
– Both: flexion
– Single: lateral flexion,
rotation
Internal Oblique
Internal oblique
Transverse Abdominis:
• Origin:
– Iliac crest, cartilage of
ribs
• Insertion:
– Pubis, linea alba
• Action:
– Compression, forced
expiration
Transverse Abdominis
Transverse abdominis