Anatomy 2 Muscle groups of the Lower Limb
Links:
Status: v103
Time: 2025-04-02
Tags: lecturenotes msk anatomy
Links: The Lower Limb
tasks:
Content:
flashcarding directives
muscles of the lower leg
action of the muscles of the lower leg
compartments of the lower leg
origins and insertions of the muscles of the lower leg
locations of the muscles of the lower leg
Objectives:
Understand the organisation of fascia and compartments of the thigh and leg
discuss the muscles acting on the lower limb joints and their functions
- hip joint
- knee Joint
- ankle joint
- subtalar joint
- interphalangeal joints
Understand the organisation of these muscles in the associated compartments
Rambles:
Tissue layers
- Skin
- Superficial fascia
- Deep fascia
- Muscle
- Bone
Fascia is like silverskin
Deep fascia decreases friction
aids venous return and forms the intermuscular septa for compartments
Compartments of the thigh and leg
the fascia lata surrounds the whole thigh like a stocking
thigh:
thigh deep fascia is called fascia lata
Anterior posterior and medial compartments
anterior is divided from the medial and posterior via the lateral and medial intermuscular septa
the posterior is divided from the medial via the posterior intermuscular fascia
lateral fascia lata is thickened into the iliotibial band certain muscles attach
Anterior muscles
Posterior muscles
Medial muscles
Leg
the crural fascia surrounds the leg like a stocking
the leg has anterior lateral and posterior compartments
most of the space is taken up by the posterior.
the interosseous membrane separates the anterior and posterior compartments and the anterior and posterior intermuscular septa separate the lateral compartment from the other 2
the leg also has the retinaculum (pleural retinacula) which is a thickening of the deep fascia which surrounds the leg like a stocking
the retinacula are:
- extensor retinaculum (dorsiflexive)?
- superior
- inferior
- fibular retinaculum (eversive?)
- superior
- inferior
- flexor retinaculum (plantarflexive)?
these act to stabilise the position of the tendons and allow smooth gliding of the tendons
Muscles of the hip joint:
Flexion:
Psoas major
Origin: T12-L5 vertebra
Insertion: Lesser Trochanter
Iliacus
Origin: Iliac fossa
Insertion: lesser trochanter
Psoas minor (if present)
Origin:
Insertion:
Rectus femoris
Pectineus
Sartorius
Tensor fascia latae
Extension:
Gluteus maximus
Origin: Gluteal surface of the ilium
Insertion: Iliotibial tract and the gluteal tuberosity
multijoint:
Semitendinosus
Semimembranosus
Biceps femoris
- long and short head
Adduction:
Pectineus
Adductor brevis
Adductor longus
Adduction magnus
adductor hiatus
Gracilis
Abduction:
Gluteus Medius
Origin: posterior iliac ridge (gluteal surface)
Insertion: greater trochanter
Gluteus minimus
Origin:gluteal surface
Insertion: greater trochanter
gluteus minimus and medius prevents hip drop when walking. trendelbergs sign is over compensation with spine to walk
rotation:
Internal rotation (turning your palms inward from an anatomical position)
gluteus medius and minimus
assisted by most adductors and the TFL(very minimally)
External rotation
Piriformis
Gemellus superior
Obturator internus
Gemellus inferior
Obturator externus
quadratus femoris
Muscles of the knee joint:
Flexion: (posterior compartment)
semimembranosus
semitendonosus
biceps femoris
sartorius is in the anterior compartment but also flexes knee
Extension: (Anterior compartment/ thigh group)
Rectus Femoris (also flexion of the hip)
vastus Medialis
vastus Intermedius
vastus Lateralis
Rotation:
Medial rotation:
Semitendinosus
Semimembranosus
Lateral rotation:
Biceps femoris
Muscles of the ankle complex:
Dorsiflexion: (Anterior compartment)
tibialis anterior
tibial tuberosity to inferior medial cuneiform and metatarsal I
extensor hallucis longus
extensor digitorum longus
Plantarflexion: posterior compartment
gastrocnemius
soleus
plantaris (if present)
Tibialis posterior
flexor digitorum longus
flexor hallucis longus
Eversion: lateral compartment
fibularis/peroneus longus and brevis
Inversion: these two are in both anterior and posterior compartment
tibialis anterior
tibialis posterior