• Iliopsoas
• Rectus femoris
• Pectineus (0-40 degrees of flx)
• Sartorius (ER comp during hip flx. Counterbalanced by TFL)
• Tensor Fascia Lata (IR comp during hip flx)
• Adductor Longus, brevis and magnus

• Iliopsoas ( main flx above 90degrees of hip flx.)
• Rectus femoris (slack w/normal sitting. poor hip flexor above 90 degrees. Slack is decreased by fully flxing knee to contribute the rectus femoris in flxn above 90)

• Glut max
• Hamstrings (biceps femoris, semimembranous, semiten)
• Adductor longus, brevis, magnus, and gracilis when hip is flexed

• Glut med (ant and post)
• Glut min (ant and post)
• TFL
• Piriformis
• Sartrorius

• Adductor Magnus, longus, brevis
• Gracilis
• Pectineus, obturator externus, quadratus femoris, lower glut max assist in adduction

• Glut max
• Glut med (post)
• Sartorius
• Obturator internus and externus
• Quadtratus femoris
• Superior gemellus
• Inferior gemellus
• Piriformis (when hip is in ext, GT moves anteriorly)

• Glut med (ant)
• Glut min
• TFL
• Piriformis (when hip is in flx GT moves posteriorly to change line of action so it has an anterior compartment to IR femoral head)

1. During knee flexion, the ACL limits medial tibial rotation by becoming tense as it wraps around PCL.
2. During knee flx, ACL limits lateral tibial rotation by becoming tense as it stretches over lateral femoral condyle

• anteromedial band- with knee flx w/medial or lateral rotation of tibia
• posteriolateral band- knee hyperextention

Tibial rotation in either direciton

Valgus and varus stress at knee

• 115-120 of flx
• good function with -5 and -10 degrees of knee ext

• Tibia rotates and glides posteriorly
• PCL blocks excessive posterior glide

• Tibia rotates and glides anteriorly
• ACL blocks excessive anterior glide of the tibia

• mechanical locking mechanism that occurs during the last 5 degrees of ext
• Bc medial femoral condyle is longer than later either IR of the femur or ER of the tibia is needed to attain max surface and produce mechanical lock.

• ER of femur relative to fixed tib with closed chain
• IR of tibia w/fixed femur with open chain
• popliteus muscle unlocks knee with closed or open chain

determines amt of ER of the tibia relative to the femur during tibiofemoral ext.

1. pt sits with hip at 90 degrees of flx and the knee flex so that lower leg hangs free
2. mark the medial and lateral borders of hte patella and the midline of the patella and tibial tuberosity
3. have pt ext knee fully and observe mvt of tibial tuberosity relative to the midline of the patella

• Biceps femoris
• TFL

• semitendinosus
• semimembranosus
• popliteus
• gracilis
• sartorius

• Compression- lateral femoral and tibial condyles
• Tension- medial ligaments and jt capsules are strained in tension which results in potential tearing and elongation

• Compression-medial ligaments and capsule will be short and weaken with the medial articular surface compressed w/ increased erosion
• Tension- Lateral L and capsule will be strained and vulnerable to tearing and elongation

males=12 degrees

females= 15 degrees

>20 degrees is abnormal and results in an increase in lateral forces on patella

• genu valgus (knock knee)
• femoral anteversion- turns feet and knees in)
• external tibial torsion
• Lateral idsplacement of tibial tuberosity

1. tightness of IT band
2. weakness of VMO
3. tightness of rec fem will hold patella cranially
4. shift in insertion site of patella L
5. change in length o hte patellar L

1. IT band tightness
2. biceps femoris tightness
3. semimembranosus and semitendinosus weakness

1. femoral anteversion
2. excessive pronation of the foot which IR tibia and femur

• anterior tibiofibular L
• posterior tibiofibular L
• interosseus tibiofibular L

LCL

• anterior talofibular L
• posterior talofibular L
• calcaneofibular L

MCL

• anterior tibiotalar L
• posterior tibiotalar L
• tibionavicular L
• tibiocalcaneal L

pronation - DEE

Dorsiflexion: posterior rotation and glide of talus

External rotation of talus

Eversion: medial glide of talus

Plantar Flexion: anterior rotation and glide of talus

Internal rotation of talus

Inversion: lateral glide of talus

Talus is fixed. Tib/Fib are moving

Dorsiflexion: anterior rotation and glide of tib/fib

Internal rotation of tib/fib

Inversion: lateral glide of the tib/fib producing inversion slight to - due to jt compression

Talus is fixed. Tib/fib are moving

Plantar flexion: posterior rotation and glide of the tibia.

External rotation of tibia

Eversion: medial glide of the tibia/fibular producing eversion is slight to 0 due to jt compression.

• 87% by LCLs
• calcaneofibular L (first)
• anterior talofibular L (2nd)
• posterior talofibular L (least)

• anterior talofibular L (LCL)
• posterior tibiotalar L (MCL)

• posterior talofibular L (LCL)
• anterio tibiotalar L (MCL)

• posterior talofibular L (LCL)
• calcaneofibular L (LCL)
• anterior tibiotalar L (MCL
• tibionavicular L (MCL)

• anterior talofibular L (LCL)
• posterior tibiotalar L (MCL)
• tibiocalcaneal L (MCL)

muscles can control ankle DF by eccentric contraction

1. gastrocnemius
2. soleus
3. tibialis posterior

What are the ankle dorsiflexors (pronators)?

These muscles can also control PF by eccentric contraction

1. Tibialis anterior
2. extensor digitorum longus and hallucis