Here’s a practical, evidence-based overview of how to prevent knee injuries and how to treat them if they happen.

Prevention — what to do now

• Build strength around the knee. Strong quadriceps, hamstrings, glutes, and hip muscles reduce stress on the joint and lower injury risk. Include 2–3 sessions/week of targeted strength work (squats, step‑ups, straight‑leg raises, hip abduction/bridges). (orthoinfo.aaos.org)
• Maintain flexibility and range of motion. Regular gentle stretching of the quads, hamstrings, calves and hip flexors helps normal knee mechanics and reduces injury risk. Warm up 5–10 minutes before stretching. (akamai.mayoclinic.org)
• Improve balance and movement technique. Single‑leg balance, proprioception drills, and training to avoid inward knee collapse (valgus) during landing or squatting lower ACL/other injury risk—especially important for athletes. (orthoinfo.org)
• Progress training gradually and cross‑train. Increase intensity, volume, or pace slowly; use low‑impact cardio (cycling, swimming, elliptical) to reduce repetitive joint load. (orthoinfo.org)
• Control body weight. Losing excess weight reduces force across the knee (every pound lost lowers knee load substantially), lowering osteoarthritis and injury risk. (AARP.org)
• Use appropriate footwear and surfaces. Shoes with proper support and cushioning for your activity and avoiding excessively hard or uneven surfaces reduce injury chances. (orthoinfo.org)
• For sports: use evidence‑based neuromuscular/ACL‑prevention programs. Programs that include plyometrics, strength, balance and technique coaching reduce ACL and lower‑extremity injury rates in athletes. (orthoinfo.aaos.org)

Immediate treatment after an acute knee injury

• First 24–72 hours: protect the knee, control swelling/pain, and avoid activities that make pain worse. Traditional RICE (rest, ice, compression, elevation) is commonly used for short‑term pain/swelling control; many clinicians now emphasize early controlled motion as tolerated rather than complete immobilization. Ice for 10–20 minutes at a time; don’t ice continuously or with direct skin contact. Use compression (ace wrap) without cutting off circulation and elevate when possible. (healthy.kaiserpermanente.org)
• Pain control: short course of acetaminophen or nonsteroidal anti‑inflammatory drugs (NSAIDs) can help—follow dosing instructions and precautions or check with a clinician. (healthy.kaiserpermanente.org)
• Don’t ignore instability or inability to bear weight: those are red flags (see below). If you can’t walk or have marked swelling, deformity, numbness, or a pop at the time of injury, seek urgent evaluation. (my.clevelandclinic.org)

When to see a clinician or go to urgent care / ER

• Unable to bear weight, severe pain, visible deformity, sudden large swelling (possible hemarthrosis), numbness or loss of pulses, or signs of infection (fever, warmth, redness). These need prompt evaluation. (my.clevelandclinic.org)

Diagnosis and treatment options (short overview)

• Initial care and diagnosis: clinician will examine, often order X‑rays (rule out fracture) and possibly MRI (soft‑tissue injuries such as ACL, meniscus, cartilage). (orthoinfo.aaos.org)
• Physical therapy (PT) is a cornerstone of treatment for sprains, strains, many meniscal problems, patellofemoral pain, and even some ACL injuries managed non‑surgically. PT focuses on swelling control, range of motion, progressive strengthening, functional retraining, and return‑to‑sport criteria. (orthoinfo.aaos.org)
• Bracing/assistive devices: short‑term knee braces or crutches may be used for support while healing. For some ACL injuries, a hinged brace is used during rehab. (orthoinfo.aaos.org)
• When surgery is needed: significant mechanical problems (locked knee, large displaced meniscal tears), persistent instability (often with ACL tears in active people), or severe cartilage/ligament damage may require arthroscopic or reconstructive surgery. Decisions depend on age, activity level, symptoms, and injury pattern. (orthoinfo.aaos.org)

Rehabilitation and return to activity

• Follow a progressive rehab plan supervised by a PT: reduce swelling, restore full range of motion, rebuild strength (especially quads/hip abductors), retrain dynamic movement patterns, and gradually return to sport‑specific drills. Typical programs run weeks to months depending on injury. (orthoinfo.aaos.org)
• Return‑to‑sport criteria should be strength and function based (symmetry of strength, hop tests, no pain or swelling, sport‑specific skills) rather than an arbitrary time only. For example, many ACL reconstructions use 6–9+ months criteria depending on progress. (orthoinfo.aaos.org)

Red flags and when to get urgent care

• Severe swelling or immediate “pop” at injury with inability to bear weight.
• Knee looks deformed, you have numbness, cold/blue foot, or cannot move toes/fingers.
• Fever with worsening knee pain or redness (possible infection).
  If any of these occur, seek urgent medical attention. (my.clevelandclinic.org)

Simple home‑exercise examples (do after checking with your clinician)

• Straight‑leg raises, wall sits (partial), mini‑squats, step‑ups, hamstring curls, bridges, calf raises, and balance drills. Start gently and increase reps/weight gradually; stop if sharp pain occurs. AAOS and Mayo Clinic have many illustrated examples. (orthoinfo.aaos.org)

Key takeaways

• Prevention focuses on strength, flexibility, neuromuscular control, gradual progression, and healthy weight. (orthoinfo.aaos.org)
• For acute injuries, protect the knee, control swelling/pain, seek evaluation for inability to bear weight or instability, and start guided rehab early. (healthy.kaiserpermanente.org)
• Physical therapy is essential for most nonoperative care and for post‑op recovery; surgery is reserved for specific injuries or when rehab fails to restore stability/function. (orthoinfo.aaos.org)

If you want, I can:

• Give a short, illustrated home‑exercise routine (beginner level) tailored to whether you have pain now or just want prevention; or
• Help you decide whether your recent knee problem needs urgent care if you describe your symptoms.