Knee Rehab Flashcards
articular cartilage structure and mechanics
- outermost layer is firm collagenous shell to withstand high force
- largest layer, gel like with high fluid and some collagen to withstand compressive forces; when compression force applied some fluid flows out through outermost layer to synovial capsule and back to gel layer when compressive force removed
- firm collagen anchoring cartilage to bone
- deepest, cartilage calcifies and hardens, intergrates into bone
common knee conditions
- patellar femoral pain syndrome and patellar tendinopathy are chronic conditions due to altered mechanics from hip/ankle, associated with overload
- ligament and mensical dmg due to trauma induced sprains, tears impact tibiofemoral stability
- osteoarthritis at the tibiofemoral or patellofemoral joint due to chronic inflammation with breakdown of joint tissues in synovial joint
osteoarthritis
pathological change:
1. hyaline cartilage and menisci thin out, losing shock absorption properties
2. subchondral bone is normally squishy to absorb shock, calcifies thus less able to withstand compressive load, bony margins get reshaped
3. synovial membrane thicken and misshapes
4. synovial fluid decreases viscosity, loses friction reduction
5. chronic pain, inflammation, stiffness
typical knee motion
- knee flexion: coupled with tibial MR, patella slides inferiorly; max ROM 130-150 deg, 60-70 deg for normal gait
- knee ext: coupled with tibial LR, patella slides superiorly; max ROM 5 deg beyong 180 deg, 175-180 deg normal gait
patella
1. Purpose
2. Forces
3. Stress
- patellar tendon is an stiff ECC E absorber for impact activities to proctect quads, slow to heal
- many struc secure the patella against femur, patellar and rec fem/vastus intermedialis tendon sup and inf, vastus lateralis and vastus medialis and lat/med reticuaculum (CT attaching patella to femoral condyles) laterally
- biomechanical deviation contribute to patellofemoral joint stress consider all three plane of motion; int rot of femur press lat femoral condyle into patella, deeper knee flex increases compressive force on patellar femoral joint (caution on level of depth of squat during rehab), greater valgus creates lat pull on patella
tibiofemoral joint stress
- load distribution between compartments change depending on varus/valgus orientation due to compromized menisci and articular cartilage (med side during varus, lat side during valgus)
- MCL and LCL during valgus and varus stress and tibial ER, musculotendinous stress on MCL from pez anserine muscle tendons pulling on it, LCL from IT band and biceps femoris tendons
- PCL stress increase with posterior tibial or anterior femoral translation during hyperflexion, descending and kneeling; ACL stress increase with hyperext, valgus, tibial LR/femoral MR; both are inside joint, harder to heal and need surgical repair
soft tissue synergies with knee from hip
- gluteus medius primary hip abductor, limit add for limited valgus
- hip lat rotator (deep dlutes) limit femoral med rot
- ITB pull on lat patellar reticulacum add to lat stress on patella
- hip extensors and ankle plantarflexors for shock absorption and propel body; lack of control may increase knee stress
- rectus femoris is a hip flexor, if tight can increase pressue of patella against femur, lengthen by stretching quad and hip
Exercises improving knee ext ROM
- CM: seated forward/backwards kick
- SS: hamstring stretch
- PNF: PNF focusing on hamstring, knee flexor fibres
- SMR: foam roll for hamstrings
exercises improving knee flex ROM
- CM: hamstring heel slides, stationary bike
- SS: standing quad stretch
- PNF: target quad, extension part of rec fem
- SMR: foam rolling quads
2 motions paired with knee flexion
tibial internal rotation due to activation of pez anserine muscles and inferior translation of the patella
2 motions pairing with knee extension
tibial external rotation due to activation of biceps femoris and superior translation of the patella
3 ways increasing patellofemoral stress
- knee flexion in weight bearing increases inferior translation and compression of patella against femur
- internal rotation of the femur presses lat femoral condyle against patella, increasing stress in medial direction
- valgus position and quad activation (esp vastus lateralis) increases lateral pull on patella
managing anterior knee pain
since patellar issues originate from poor hip and ankle biomech and overload, focus on opening tissues that improve mechanics since ROM is not limited by tissue healing
managing osteoarthritis
Optimize mobility while keeping joint compression and shear tolerable by using enough load, no healing focus since OA is chronic progressive condition
managing menisco-ligamentous
- during inflammation, there is acute joint effusion limiting ROM and muscle guarding (esp higher hamstring activation and decreased quad activation), therefore work within ROM and gradually increase ROM
- during repair and remodelling, progressively restore full ROM, while decreasing hamstring tone, and strengthening quads
knee mobility: stationary bike
- flexion ROM: passive motion by pushing with non-pathological side, increasing active motion by increasing work by pathological side
- increase the seat height to decrease flexion, decrease to increase flexion
- limitations: ankle mobility, may not be able to get on or off bike, don’t know how to ride, access to equipment
knee mobility: elevated heel slides
flexion ROM: can work supine or elevation (gravity help draw knee into flexion and increases fluid drainage from extremity, push back up using opp side), can use res band or towel to aid in ROM
knee mobility: heel prop w/ or w/o over pressure
ext ROM: prop heel up on elevated surface, gravity will exert force for passive creep effect to extend hamstrings, therapist can assist by putting downward pressure to increase knee ext
