Anterior Tibialis

Origin - Lateral condyle & proximal 2/3 of the lateral surface of the tibia

Insertion - Meidal & plantar aspects of the medial cuneiform & the base of the 1st metatarsal

Isolated Function - Concentrically accelerates dorsiflexion & inversion

Integrated Function - Eccentrically decelerates plantarflexion & eversion

Isometrically stabilizes the arch of the foot

Posterior Tibialis

Origin - Proximal 2/3 of posterior surface of the tibia & fibula

Insertion - Every tarsal bone (naviular, cuneiform, cuboid) but the talus plus the bases of the 2nd through the 4th metatarsal bones. The main insertion is on the navicular tuberosity & the medial cuneiform bone

Isolated Function - Concentrically accelerates plantarflexion & inversion of the foot

Integrated function - Eccentrically decelerates the dorsiflexion & eversion of the foot

Isometrically stabilizes the arch of the foot

Soleus

Origin - Posterior sruface of the fibular head & proximal 1/3 of its shaft & from the posterior side of the tibia

Insertion - Calcaneus via the achilles tendon

Isolated Function - concentrically accelerates plantarflexion

Integrated Function - decelerates ankle dorsiflexion

 isometrically stabilizes the  foot & ankle complex

Gastrocnemius

Origin - Posterior aspect of the lateral & medial femoral condyles

Insertion - Calcaneus via the achilles tendon

Isolated Function - Concentrically accelerates plantarflexion

Integrated Function - Decelerates ankle dorsiflexion

Isometrically stabilizes the foot & ankle complex

Peroneus Longus

Origin - lateral condyle of tibia, head, and proximal 2/3 of the lateral surface of the
fibula

Insertion - Head of the fibula

Isolated Function - Concentrically plantarflexes & everts the foot

Integrated Function - Decelerates ankle dorsiflexion

Isometrically stabilizes the foot & ankle complex

Biceps Femoris - Long Head

Origin - Ischial tuberosity of the pelvis, part of the sacrotuberous ligament

Insertion - Head of the fibula

Isolated Function - Concentrically accelerates knee flexion & hip extension

Tibial external roation

Integrated Function - Eccentraically decelerates knee extension

Eccentrically decelerates hip flexion

Eccentracially decelerates tibial internal rotation at mid-stance of the gait cycle

Isometrically stabilizes the LPH complex & knee

Biceps Femoris - Short Head

Origin - Lower 1/3 of the posterior aspect of the femur

Insertion - Head of the fibula

Isolated Function - Concentrically accelerates knee flexion & tibial external rotation

Integrated Function - Eccentrically decelerates knee ext

Eccentrically decelerates tibial internal rotation

Eccentrically stabilizes the knee

Semimembranosus

Origin - Ischial tuberosity of the pelvis

Insertion - Posterior aspect of the medial tibial condyle of the tibia

Isolated Function - Concentrically accelerates knee flexion, hip ext, & tibial internal rotation

Integrated Function - Eccentrically decelerates knee extension

Eccentrically decelerates hip flexion

Eccentrically decelerates tibial external rotation

Isometrically stabilizes the LPH complesx & knee

Vastus Lateralis

Origin - Anterior & inferior border of the greater trochanter, lateral region of the gluteal tuberosity, lateral lip of the linea aspera of the femur

Insertion - Base of patella and tibial tuberosity of the tibia

Isolated Function - Concentrically accelerates knee extension

Integrated Function - Eccentrically decelerates knee flexion, adduction, and internal rotation

Isometrically stabilizes the knee

Semitendinosus

Origin - Ischial tuberosity of the pelvis & part of the sacrotuberous ligament

Insertion - Proximal aspect of the medial tibial condyle of the tibia (pes anserine)

Isolated Function - Concentrically accelerates knee flexion, hip extension, and tibial internal rotation

Integrated Function - Eccentrically decelerates knee extension

Eccentrically decelerates hip flexion

Eccentrically decelerates tibial external rotation

Isometrically stabilizes the LPH complex and knee

Vastus Medialis

Origin - Lower region of intertrochanteric line, medial lip of linea aspera, proximal medial supracondylar line of the femur

Insertion - Base of patella, tibial tuberosity of the tibia

Isolated Function - Concentrically accelerates knee extension

Integrated Function - Eccentrically decelrates knee flexio, adduction, & internal rotation

Isometrically stabilizes the knee

Vastus Intermedius

Origin - Anterior-lateral regions of the upper 2/3 of the femur

Insertion - Base of the patella, tibial tuberosity of hte tibia

Isolated Function - Concentrically accelerates knee extension

Integrated Function - Eccentrically decelerates knee flexion, adduction, and internal rotation

Decelerates hip extension

Isometrically stabilizes the LPH complex & knee

Rectus Femoris

Origin - Anterior-inferior iliac spine of the plevis

Insertion - Base of patella, tibial tuberosity of the tibia

Isolated Function - Concentrically accelerates knee extension and hip flexion

Integrated Function - Eccentrically decelerates knee flexion, adduction, & internal rotation

Decelerates hip extension

Isometrically stabilizes the LPH complex & knee

Adductor longus

Origin - Anterior surface of the inferior pubic ramus of the pelvis

Insertion - Proximal 1/3 of the linea aspera of the femur

Isolated Function - Concentrically accelerates hip adduction, flexion, and internal rotation

Integrated Function - Eccentrically decelerates hip abduction, extension, and external rotation

Isometrically stabilizes the LPH complex

Adductor Magnus - Anterior Fibers

Origin - Ischial ramus of the pelvis

Insertion - Linea aspera of the femur

Isolated Function - Concentrically accelerates hip adduction, flexion, & internal rotation

Integrated Function - Eccentrically decelerates hip abduction, extension, and external rotation

Dynamically stabilizes the LPH complex

Adductor Magnus - Posterior Fibers

Origin - Ischial tuberosity of the pelvis

Insertion - Adductor tubercle of femur

Isolated Function - Concentrically accelerates hip adduction, extension, & external rotation

Integrated Function - Eccentrically decelerates hip abduction, flexion, & internal rotation

Isometrically stabilizes the LPH complex

Adductor Brevis

Origin - Anterior surface of the inferior pubic ramus of the pelvis

Insertion - Proximal 1/3 of the linea aspera of the femur

Isolated Function - Concentrically accelerates hip adduction, flexion, and internal rotation

Integrated Function - Eccentrically decelerates hip abduction, extension and external rotation

Isometrically stabilizes the LPH complex

Gracilis

Origin - Anterior aspect of lower body of pubis

Insertion - Proximal medial surface of the tibia (pes anserine)

Isolated Function - Concentrically accelerates hip adduction, flexion, & internal rotation

Assists in tibial internal rotation

Integrated Function - Eccentrically decelerates hip abduction, extension, & external rotation

Isometrically stabilizes the LPH complex & knee

Pectineus

Origin - Pectineal line on the superior pubic ramus of the pelvis

Insertion - Pectineal line on the posterior surface of the upper femur

Isolated Function - Concentrically accelerates hip adduction, flexion, and internal rotation

Integrated Function - Eccentrically decelerates hip abduction, extension, & external rotation

Isometrically stabilizes the LPH complex

Gluteus Medius - Anterior Fibers

Origin - Outer surface of the ilium of the pelvis

Insertion - Lateral surface of the greater trochanter on the femur

Isolated Function - Concentrically accelerates hip abduction & internal rotation

Integrated Function - Eccentrically decelerates hip adduction & external rotation

Isometrically stabilizes the LPH complex