The Lower Extremity: Knee, Ankle, Subtalar Joints Chapter 10 & 11:

Tibiofemoral Joint (KNEE JOINT)
o Modified hinge joint
o Two condyles of femur articulate with tibial plateaus/menisci
o Note: Intercondyloid eminence & notch: ACL tear
o Patella articulates with patella surface of femur
o patellofemoral joint
o Bony stability is WEAK
o helped by considerable ligaments & cartilage





Landmarks of Knee Joint
Femoral Condyles
Tibial Plateau
Intercondyloid Eminence & Notch
Tibial Tuberosity
Fibular Head





Structures of the Knee
Articular Cartilage
Synovial membrane, cavity, fluid
Meniscus
Quadriceps Tendon
Patellar Tendon








The Tibiofemoral Structure
Menisci are circular rims of cartilage
Lateral & Medial
Provide shock absorption
Protect bony ends
 stability of knee
Outer portion is thicker & thicker than inner
Outer portion more vascular, blood supply minimal by 20’s
Medial menisci attached to plateau firmly, whereas lateral menisci has greater freedom of movement




Ligamentous Support
ACL prevents anterior displacement of tibia
PCL prevents posterior displacement of tibia
Medial collateral resists valgus forces
Lateral collateral resists varus forces



“Q” Angle
angle formed b/t longitudinal axis of femur, (line of pull of quadriceps) & line that represents pull of
patellar tendon
normally <15 º in men & < 20 º in women
Larger angle may cause…
o Hip Bursitis
o Ilio-tibial Band Syndrome
o Patellar Tracking Problems
o Knee Meniscus Tears
o At ankle, excessive foot pronation
o Plantarfasciitis
o Achilles tendonitis
Movements
 Flexion: bending or decreasing angle between femur & leg, characterized by heel moving toward buttocks
 Extension: straightening or increasing angle between femur & lower leg
o External rotation: rotary movement of tibia laterally away from midline
o Internal rotation: rotary movement of tibia medially toward midline
o Neither will occur unless flexed  20-30 degrees

Rectus Femoris: Flexion of hip

Vastus Lateralis: Extension of knee

Vastus Medialis: Extension of knee

Vastus Intermedius: Extension of knee

Semitendinosus :

Semimembranosus

Biceps Femoris

Gastrocnemius: *Plantar flexion of ankle






Common Disorders of the Lower Extremity
What You Should Know About These Injuries?
What is happening with injury, what is it?
What structures are involved (joint, muscles, landmarks, ligaments, tendons, etc.)?
What factors, situations, postures, exercises contribute to it or make people prone to it?
What can I do to prevent or reduce the chance that this happens in my client/student/athlete?
**Goal is to know enough about these conditions that we can address them whenever we work with
client/student/athlete.

o

o

o
o

Ilio-Tibial (IT) Band Syndrome
Inflammation of IT band due to repetitive rubbing against lateral condyle of femur
pain on lateral aspect of knee
Caused by tightness of IT band
also weakness Tensor Fasciae Latae
Occurs in exercisers in which knee & hip joint repetitively move only in sagittal plane
also excessive movement of femur into adduction
bikers, runners
Prevention: recognizing those at risk, signs/symptoms, stretching of hip abductors & strengthening gluteus
medius

Piriformis Syndrome
Tightness of the piriformis muscle compressing the sciatic nerve contributing to pain down the posterior
aspect of the leg
o lack of stretching into internal rotation
o extensive hip extension and abduction strengthening exercises
o
o
o
o

o

Medial Collateral Ligament Strain
Direct blow to lateral aspect of knee
Repetitive valgus force (“breast strokers knee”, incorrect exercises)
Excessive Q angle (“knock knees” genu valgum)
pronated feet,
Lateral Collateral Ligament Sprain
opposite forces varus force, “bowed-leg” genu varum
For both, be aware of structural mechanics (pronated/supinated, feet), gradual progression into activities
that contribute, backing off when pain begins, proper strengthening, proper form

o
o

o

o

o

o
Chondromalacia
Degeneration of cartilage on articulating surface of patella
due to patella rubbing on femoral condyle
creates pain, on movement, swelling, grating sensation during knee extension/flexion
Primary cause:
Patellar Tracking problems due to tightness of vastus lateralis or weakness of vastus medialis
Strengthen vastus medialis by training into complete extension
short arch quads (0-30º of extension)
Look for structural imbalances for those predisposed:
genu valgum, tibial torsion, pronated feet
Be aware of activities that may contribute
cycling, recovering from knee problems
Osgood Schlatter Disease
 Repeated overuse of knee extensors creating tendonitis of patellar tendon on tibial tuberosity
o especially during growing periods
 Swelling, pain on activity & kneeling
 Treatment:
o early recognition
o rest and ice
o Stop exercises that involve knee extension (quads)
o Cho-Pat








Anterior Cruciate Tears
Valgus force with rotation while weight bearing
Excessive flexion of weight bearing knee (skiing/squats)
Anterior blow to femur with foot fixed (anterior translation of tibia)
Prevention
Train hamstrings
Train eccentrically
Train knee proprioceptors
Increase fitness to minimize fatigue
Posterior Cruciate Tear
 Posterior translation of tibia relative to femur
o anterior blow to tibia
 Avoid hyperextension of knee

o
o

o
o


o
o
Meniscal Tears
Medial meniscus tends to be damaged more than the lateral due to…
medial meniscus has less ability to move in the knee joint
more stresses on knee tend be directed to medial meniscus
Major Contributing Factors to tears
Direct contact
Excessive pounding
unless necessary only 3 distance runs per week, use other CV methods
Proper shoe support, proper running surfaces
Twisting on a weight bearing knee
Excessive flexion on a weight bearing knee
Mechanics of Knee in Flexion


o
o
o
o
o
Hamstring Strains
Tear in belly of muscle or tendonosus tissue
Caused by muscular imbalance of quads/hams, fatigue, poor flexibility
sudden change in direction or speed
Improper warm up/poor flexibility
Quadriceps to hamstring strength ratio (3:2)
hamstrings must “brake” quads to prevent anterior translation of tibia
**weakness to hamstrings (train them functionally!!)










So What Are You Going to Do About It?
Assess Static Posture
Assess Controlled Dynamic Movement
Identify Previous Injuries to the lower extremities
Identify High Risk & Initiate a Corrective Program
“Don’t Just Train on the Sagittal Plane”
Focus on Eccentric Contractions
Train Proprioceptors to dynamically stabilize knee
Train on Single Leg
Demand Perfect Form in EVERYTHING they Do
MOST IMPORTANTLY… Educate them on proper body mechanics


Neuro-Muscular Training of Knee Stabilizers & Proprioceptors
Exercises to Protect ACL
Ankle & Subtalar Joints
Chapter 11THE ANKLE AND SUBTALAR JOINTS
 Talocrural (ankle) Joint: hinge joint
 Articulation of talus with distal ends of tibia & fibula
o OK bony structure with strong ligament support
 Subtalar joint – talus & calcaneous
o inversion & eversion of heel
Joints
 Tibiofibular joint
o joined at both proximal & distal tibiofibular joints
o Ligaments and a strong, dense interosseus membrane b/t tibia & fibula shafts provide support
o Minimal movement possible
o Distal joint becomes sprained occasionally in heavy contact sport
 “high ankle sprains”

Bones
Distal malleoli of tibia (medial) & fibula (lateral)
o serve as pulley for posterior tendons to increase mechanical advantage of muscles in performing
inversion & eversion actions





Bones of Foot
Tibia articulates with talus
Talus articulates with calcaneus
7 tarsal bones (each foot)
5 Metatarsal bones (each foot)
14 phalanges (each foot)
o
o
o
o
o
o
Movements
Dorsiflexion (flexion): movement of top of ankle & foot toward anterior tibia
Plantar flexion (extension): movement of ankle & foot away from tibia
Eversion: turning ankle & foot outward; away from midline; weight is on medial edge of foot
Inversion: turning ankle & foot inward; toward midline; weight is on lateral edge of foot
Pronation: combination of eversion, dorsiflexion & abduction (toe-out)
Supination: combination of inversion, plantar flexion & adduction (toe-in)

Muscles
Lower leg - divided into 4 compartments bound by fasciae
o facilitates venous return & prevents excessive swelling of muscles during exercise
 Anterior compartment: dorsiflexion & inversion group
 Lateral compartment: eversion of foot
 Posterior Compartment: superficial & deep
o Plantar flexes & can invert & evert foot

Gastrocnemius: Plantar flexion of ankle




Soleus : Plantar flexion of ankle
Tibialis Anterior
Tibialis Posterior
Peroneals
Common Disorders of the Lower Extremity
 Anterior, Posterior, Lateral Compartment of Lower Leg
o Anterior: Tibialis anterior
o Lateral: Evertors
 Posterior: Deep: Tibialis posterior: Superficial: Gastrocnemius & soleus
 Over use of the above muscles causes swelling  pressure in compartment along with microtears on the
periosteum
 Reducing Risk of Developing Compartment Syndrome, Medial Tibial Stress Syndrome or “shin splints”
 Pain in lower leg caused by swelling of muscles in compartment (compartment syndrome) or tearing of
muscle attachment to periosteum of tibia (MTSS or shin splints)
o anterior or deep posterior are most common
o

o
o

o
o
o

o



seen mostly in those running too much too quickly
Look at structure of LE
Hips, knees (genu valgum)
especially pronated (everted) foot
Check shoes support (cushioning)
proper arch support
wear on shoe (inside, outside, front, back)
don’t wear cleats for jogging purposes (wrestlers)
Proper flexibility
especially gastroc/soleus (why?)
Gradual increases in exercises especially running (“10% Rule”)
Allowing for adequate rest, prevent overuse (runners?)
Consider weight, fitness level, age, hills/flat running, surfaces

o



The Ankle: Sprains
Mostly seen in the lateral ligaments
stretched or torn
Forceful inversion/supination of the foot
Pain, Swelling, Disability
Structural conditions, proper foot support (wide base), running surface, proprioceptive training, shoes worn
on outside
“High Ankle Sprains”
 Ankle Syndesmosis called high ankle sprain because is occurs above ankle joint
o 1 of 3 ligaments are injured
 Occurs many times when foot is forced “upward/outward” “everted or pronated”
 Skiiers and football players have high incidence
Prevention of Ankle Sprains
“Don’t Just Train on the Sagittal Plane”





Plantar Fascia
Thick connective tissue which supports the arch of the foot
o runs from calcaneus to head of metatarsals
Undergoes tension when weight bearing
o carries 15% of total load of foot
Also act as spring during gait cycle to propel us forward
Fascia may be overworked with…
o excessive running
 hard surfaces
o poor arch support
o poor foot mechanics
o flat feet
o excessive pronation
o high arches
o Muscle imbalances
o tight Achilles tendons
o May lead to bone spurs
Prevention of Plantar Fasciitis
Check mechanics of lower leg/foot





Review history of running problems
Proper foot support (shoe/insert)
o look for wear patterns on shoe
Gradual progression into heavy weight bearing activities (10% rule)
Minimize running on hard surfaces
Proper warm with stretching prior to running
o stretching out of bed
Maintain strength/flexibility of lower leg muscles, back down at first signs
Massage/Cold can roll
After exercise ice heel



Normal Alignment of Lower Extremities
Level pelvis: heck at anterior superior iliac spine (ASIS)
Slight inward angle of femur: *note: Women wider pelvis, > inward femur angle
Patella faces forward (tells us about alignment of femur); Tibia straight; Feet face forward
























Misalignments of Lower Extremities
Genu Varum (“bow legged”)
Genu Valgum (“knocked Kneed”)
“Q” angle – angle created b/t quadriceps & patellar tendon
o larger the Q angle the greater the valgus force
“Valgus Force” on Knee – outside (lateral) to inside (medial) force
“Varus Force” on Knee – inside (medial) to outside (lateral) force
Rotations of the Lower Extremity
Femur can internally or externally rotate; Tibia can internally or externally rotate (only when knee is flexed)
Foot can abduct or adduct; Sometimes motions occur together
All are normal motions of the lower extremities
o however, structural & muscle imbalances, poor posture or perform exercises incorrectly, can
fixate joints in these positions, wearing joint & created problems
With Your Partner, answer the following questions without notes or books
Describe what IT band syndrome is, what symptoms would someone experience, who is prone to it, why
does it occur, & what can you do to reduce chance of developing it?
Describe what chondomalacia is, what symptoms would someone experience, who is prone to it, why does
it occur, & what can you do to reduce chance of developing it?
Describe what Osgood-schlatters is, what symptoms would someone experience, who is prone to it, why
does it occur, & what can you do to reduce chance of developing it?
Your student has poor arch support in their shoes and has been increasing their distance in running over the
last 2 months and is now complaining of discomfort in the knee. Specifically state which area of the knee
may be irritated and why.
What are the prime movers at the knee in the upward phase of the squat exercise?
If the foot is planted & a forward to backward blow is given to the tibia, what ligament may be damaged?
What structure of the knee may be damaged, when stepping up & twisting to the side during step aerobics?
What 2 motions occur at the subtalar joint?
What would one expect to see at the bottom of the shoe in someone who’s foot tends to pronate?
Discuss what is meant by internal and external rotation of the tibia and what conditions can contribute
Note origin and insertion of all quadriceps, hamstring, and gastroc. muscles (discuss function of each)
On knee with springs notice how the ACL, PCL, MCL, LCL hold the knee joint together
Meniscal Tear