General Guidelines — Knee Pathologies
- Watch knee alignment very carefully — the patella should always track directly over the 2nd and 3rd toes.
- Strive for full extension but avoid hyperextension (cue co-contraction of the quads and hamstrings).
- Improving balance and proprioception is important for all knee injuries.
- Avoid jumping and deep knee bending unless advanced and/or asymptomatic (e.g. post-ACL or meniscectomy).
- Jump Board can be great for re-training athletes to land properly after surgery and for injury prevention.
- Improper patellar tracking is caused by weak hip abductors — strengthen gluteus medius.
- Quads are often too strong and hamstrings too weak — strengthen and stretch both for muscle balance.
Meniscal Injuries
The mechanism is usually a sudden rotation of the femur on a fixed tibia with the knee flexed; can also result from degeneration in older adults with no specific mechanism. The medial meniscus is torn more often than the lateral. Healing depends on tear location — peripheral tears can regenerate (good blood supply) but central tears cannot, and may need meniscectomy or repair via arthroscopy.
- MOI: femur rotates on a fixed, flexed knee
- Medial meniscus torn more often
- Peripheral tears heal; central tears can't
- Aggravated by weight-bearing & twisting
Symptoms: Knee pain, limited tolerance to sitting and walking, locking/popping/clicking, localized tenderness, limited ROM, and mild-to-moderate swelling depending on tear severity. Aggravated by weight-bearing (kneeling, squatting, walking) and twisting.
- Watch knee alignment carefully — patella should track over the 2nd and 3rd toes.
- Strengthen all the muscles surrounding the knee.
- Strive for full extension but avoid hyperextension (cue quad/hamstring co-contraction).
- Avoid loaded deep knee bending, kneeling, and twisting.
- Avoid loaded deep knee bending.
- Avoid kneeling.
- Avoid twisting maneuvers.
Strengthen all the muscles surrounding the knee joint.
Closed-Chain Stability & Alignment
Eccentric Quad Strengthening
Hamstring & Posterior Chain
ACL Tear
The anterior cruciate ligament restrains anterior displacement of the tibia on the femur and limits knee rotation. Mechanism is typically a planted foot with a flexed knee and the tibia rotating while the body continues forward. More common in women (anatomy, lower hamstring strength, biomechanics). Because the ACL is key to knee stability, surgery is usually recommended for active people; rehab is lengthy (6 months to 1 year).
- Restrains anterior tibial glide & limits rotation
- MOI: planted foot, flexed knee, rotation
- More common in women
- Rehab takes 6 months to 1 year
Symptoms: Acute: an audible 'pop' at injury, pain, a feeling of 'giving way', swelling, decreased ROM. Chronic: knee instability, lack of eccentric quadriceps strength, poor balance and proprioception.
- Favor closed-chain exercises to promote stability.
- Emphasize eccentric quad strengthening, balance, and proprioception.
- Jump Board can be great for re-training proper landing after surgery and for prevention (advanced/asymptomatic).
- Build core strength and dynamic hip control — proximal factors drive knee mechanics.
- No weighted open-chain knee extension (e.g. the gym knee-extension machine).
- Avoid twisting maneuvers.
Closed-chain exercises to promote stability, core strengthening, balance and proprioception, and eccentric quad strengthening.
Closed-Chain Stability & Alignment
Eccentric Quad Strengthening
Balance, Proprioception & Functional
Knee Osteoarthritis (DJD)
A progressive disorder in which the smooth articular cartilage wears away until bare bone is exposed; the joint space narrows and bones rub ('bone on bone'). Knee OA is the most common type of osteoarthritis — roughly 13% of women and 10% of men over 60 have symptomatic knee OA, rising to ~40% over age 70. Caused by previous injury, ligament/meniscal injury affecting alignment, repetitive strain, genetics, and obesity.
- Most common type of osteoarthritis
- ~40% prevalence over age 70
- 'Bone on bone' as cartilage wears
- Worse after activity; stiff after prolonged sitting
Symptoms: Pain, stiffness, limited ROM, localized swelling, developing gradually over years. Pain is usually worse after activity (especially overuse) and stiffness worsens after prolonged sitting. Initially painful only with weight-bearing; becomes continuous as it progresses.
- Limit unilateral weight-bearing and avoid heavy loads on the knee.
- Maintain/increase strength and ROM without provoking inflammation or joint damage.
- Suggest cycling and swimming over walking/running for aerobic work; encourage weight loss to reduce joint load.
- Note: Hamstring Curl is flagged in studio notes as not for OA (too much one-sided loading); avoid the kneeling position.
- Limit unilateral weight-bearing exercises.
- Avoid heavy loads on the knee joint.
- Avoid the kneeling position.
Maintain or increase strength and ROM without causing further inflammation or joint damage; reduce load (weight loss) and prefer low-impact aerobic work.
Closed-Chain Stability & Alignment
Eccentric Quad Strengthening
Balance, Proprioception & Functional
Total Knee Replacement (TKR)
Joint-replacement surgery for a knee damaged by arthritis — the most common joint replacement (followed by hip). The ends of the femur and tibia (and usually the patella) are resurfaced with artificial materials. Over 1 million TKRs were done worldwide in 2021. Unicompartmental (partial) replacements are increasingly popular when damage is localized, with faster recovery.
- Most common joint replacement surgery
- Femur, tibia (usually patella) resurfaced
- Partial (unicompartmental) recovers faster
- Post-op: regain flexion ROM & strength
Symptoms: Post-op: stiffness, loss of ROM (especially flexion), and weakness of the quads, hamstrings, glutes, and gastrocnemius/soleus.
- Encourage flexion ROM recovery.
- Strengthen quads, hamstrings, abductors, adductors, and gastrocnemius.
- Avoid high-impact work, deep knee bending, and kneeling.
- Watch alignment (patella over 2nd/3rd toes) and build balance/proprioception.
- Avoid high-impact exercises.
- Avoid deep knee bending.
- Avoid kneeling.
Encourage flexion ROM and strengthen quads, hamstrings, abductors/adductors, and gastrocnemius.
Closed-Chain Stability & Alignment
Hamstring & Posterior Chain
Balance, Proprioception & Functional
Patellofemoral Pain Syndrome (Runner's Knee)
Pain in the front of the knee, accounting for 25–40% of knee problems in sports-medicine clinics. Sometimes from softening/roughening of the cartilage under the kneecap (chondromalacia patellae). Contributing factors: glute-med weakness, abnormal hip/knee/foot alignment, patellar malalignment, and muscle imbalances (tight hamstrings/calves, weak quads). Affects more women than men (2:1), typically adolescents through twenties.
- 'Runner's knee' — 25–40% of knee problems
- Key driver: glute-med weakness & malalignment
- Women 2:1; teens to twenties
- Worse going down stairs, squatting, sitting
Symptoms: Anterior knee pain aggravated by sitting with bent knees, squatting, jumping, or stairs (especially going down). A catching, popping, or grinding sensation with knee movement is common.
- Strengthen the muscles supporting the knee — especially frontal-plane (glute med) to normalize hip/pelvis biomechanics; improper patellar tracking is driven by weak hip abductors.
- Stretch hamstrings and gastrocnemius and mobilize the IT band.
- Improve balance, proprioception, and core stability.
- Avoid loaded deep knee bends; use caution with kneeling and quadruped.
- Avoid loaded deep knee bends.
- Use caution with kneeling and quadruped positions.
Strengthen the muscles supporting the knee (primarily frontal-plane) to normalize hip/pelvis biomechanics; stretch hamstrings and calves, mobilize the IT band, and improve balance and core.
Closed-Chain Stability & Alignment
Balance, Proprioception & Functional
Hamstring & Posterior Chain
Iliotibial Band Syndrome
The IT band is the fascial continuation of the TFL, gluteus medius, and gluteus maximus, crucial for stabilizing the knee during running. Continual rubbing over the lateral femoral condyle with repeated knee flexion/extension can inflame the area. It's the leading cause of lateral knee pain in runners and cyclists. Causes include banked-surface running, poor warm-up, ramping distance too fast, weak hip abductors, overpronation, and sagittal-plane muscle imbalances; also common in pregnancy.
- Leading cause of lateral knee pain in runners
- IT band = TFL + glute med + glute max fascia
- Linked to weak hip abductors
- Pain often intensifies over time, persists after activity
Symptoms: A stinging sensation just above the knee on the outside, or along the whole IT band. Pain may not occur immediately but intensifies over time and can persist after activity; may also appear below the knee where the ITB attaches to the tibia. Chronic cases show swelling/thickening over the femur. In pregnancy: tenderness on the outside of the hip.
- Foam-roll massage the band and strengthen frontal-plane muscles (hip abductors and adductors).
- Stretch hamstrings, calves, and quads.
- Promote knee stability via closed-chain exercises.
- Avoid jumping and high-impact activities.
- Avoid jumping and high-impact activities.
Foam-roll massage, strengthen frontal-plane muscles (hip abductors/adductors), stretch hamstrings/calves/quads, and promote knee stability via closed-chain work.
Closed-Chain Stability & Alignment
Hamstring & Posterior Chain
Balance, Proprioception & Functional
Patellar Tendinopathy (Jumper's Knee)
A painful condition from small tears in the patellar tendon/ligament connecting the quads to the patella and tibia — inflammation (-itis) or degeneration (-osis) of the quadriceps tendon and/or patellar ligament. The tendon is highly stressed in jumping, landing, acceleration, deceleration, and cutting. Tendinosis develops over time with microtears and collagen degeneration. Primarily affects young athletes (15–30) in basketball, volleyball, jump events, tennis, football; more common in men.
- Microtears in the patellar tendon/ligament
- Jumping/landing sports (basketball, volleyball)
- Young athletes 15–30; more common in men
- Eccentric quad work maximizes recovery
Symptoms: Anterior knee pain and tenderness just below the kneecap; aching and stiffness after exertion. Pain aggravated by quad contraction, prolonged sitting, squatting, stair climbing, and high-impact activity. Calf weakness, quad tightness, and thickening of the tendon compared to the other knee.
- Centerpiece is a quadriceps strengthening program — especially eccentrics, which maximize tendinosis recovery.
- Strengthen other weight-bearing groups (calves) to decrease load on the patellar tendon.
- Normalize hip/pelvis alignment via core and glute strengthening.
- Avoid jumping and anything that aggravates symptoms.
- Avoid jumping or activities that aggravate symptoms.
Quadriceps strengthening, particularly eccentrics; strengthen calves to offload the tendon; normalize hip/pelvis alignment with core and glute work.
Eccentric Quad Strengthening
Closed-Chain Stability & Alignment
Hamstring & Posterior Chain