Stronger leg muscles can help support the knee during walking, stairs, and daily activity. But a list of exercises is not a diagnosis, and the same routine will not suit every painful knee.
This guide explains five common strengthening options and the questions to ask before using them. If you have a recent injury, ongoing swelling, or a knee operation behind you, follow your care team's plan rather than starting a general routine on your own.
Quick answer
Five common options are straight-leg raises, supported partial squats, low step-ups, standing hamstring curls, and calf raises. They work different muscles around the leg, so each serves a different purpose.
Your starting point depends on pain, balance, movement, and any medical restrictions. Ask a clinician or physical therapist which exercises fit your knee, how much to do, and how to progress. Exercise should not cause knee pain.
What you should know
The quadriceps are the muscles at the front of the thigh. They help straighten the knee and control the leg as you sit down or step down. The hamstrings at the back of the thigh help bend the knee. Muscles around the hip and calf also contribute to how the leg moves and supports your weight.
A strengthening plan should match what is limiting you. For one person, the main challenge may be standing from a chair. For another, it may be controlling a step down or returning to sport. Those goals help a physical therapist choose movements and judge progress.
Do not assume that pain always means weak muscles. Joint problems, tendon injuries, and other conditions can change which exercises are suitable. An assessment can help separate an exercise problem from something that needs a different approach.
How it works
These are common options to discuss with your care team, not a sequence everyone must complete.
Straight-leg raise. Lie on your back with one knee bent. Keep the other leg straight, tighten the front of that thigh, and lift the leg slowly. Lower it with control. Ask for help if you cannot keep the knee straight.
Supported partial squat. Hold a stable support and bend your hips and knees a small amount, then stand. Stay within a comfortable range. A deeper squat is not automatically a better exercise.
Low step-up. Step onto a low, stable platform, then lower yourself slowly. Use support for balance. The step height and movement range should fit your current ability.
Standing hamstring curl. Hold a stable support and slowly bend one knee to bring the heel behind you. Lower the foot without swinging the leg.
Calf raise. Hold a stable support, rise onto the balls of your feet, and lower slowly. Ask your therapist how much weight to place through each leg.
For any of these, control matters more than speed. Your clinician should set repetitions, resistance, and rest based on your condition and response. A routine written for someone else may progress too quickly or use movements that are not right for you.
How it compares
You do not need to start with every exercise or buy equipment before getting guidance. Different movements ask the leg to work in different ways.
| Exercise | Main movement | Planning question |
|---|---|---|
| Straight-leg raise | Lift a straight leg while lying down | Can I keep the knee straight without pain? |
| Supported partial squat | Bend and straighten while standing | What depth is appropriate for me? |
| Low step-up | Step up and control the descent | What step height and support should I use? |
| Hamstring curl | Bend the knee while standing | Can I move without swinging or straining? |
| Calf raise | Lift and lower the heels | How much weight should each leg carry? |
The table can help you describe a difficulty at an appointment. It cannot tell you whether an exercise is safe for a particular injury or operation.
How to decide
Before you start, ask which movements are allowed and which should wait. This is especially important after surgery, because restrictions depend on the procedure and the tissues that need to heal.
During an exercise, pay attention to pain and control. Stop if the knee hurts. Do not add weight or depth to push through discomfort. Let your clinician know if an exercise repeatedly causes symptoms so the plan can be adjusted.
Also watch how the knee responds afterward. New swelling, locking, or giving way should prompt a conversation with your care team. Seek prompt assessment after an injury if you cannot bear weight or the knee is visibly deformed.
Useful questions include: How often should I exercise? What should the movement look and feel like? What signs mean I should stop? When should we review progress? Clear answers are more useful than a universal repetition target.
Plan around your daily activities
Bring your real activity goals to an appointment. Explain whether you want to manage stairs more comfortably, stand longer at work, walk for exercise, or return to a particular sport. Also mention any equipment or support you have at home.
Atlanta Sports Medicine Institute can assess your knee concerns and discuss appropriate next steps. Read about knee pain or joint preservation for more context before requesting an appointment.
