How to Keep the Right Knee Flexed in a Golf Swing

Losing flex in your right knee is one of the quickest ways to kill power and consistency in your golf swing. If you find yourself swaying, standing up out of your posture, or struggling with solid contact, there's a good chance your right leg action is the cause. This guide will walk you through exactly why maintaining that knee flex is so important, show you the common mistakes amateurs make, and give you practical, easy-to-follow drills to finally nail this fundamental part of the golf swing.

Why a Flexed Right Knee is a Game-Changer

Before we learn how to fix something, it helps to understand why it matters. Think of your lower body as the engine of your swing and the foundation of your posture. Your right knee plays a huge part in keeping that engine running smoothly and that foundation stable. Here’s the breakdown:

• It Creates Separation and Power: The golf swing is a rotational action. To create power, you need to create a "coil" where your upper body turns more than your lower body. Keeping your right knee flexed stabilizes your lower half, allowing your hips and shoulders to turn against it. This separation builds up tension, like stretching a rubber band. When you straighten your right leg, you lose that stable base. Your hips turn too much, the tension is lost, and you have nothing to unwind against on the downswing. The coil is gone, and so is your potential power.
• It Maintains Your Swing Posture: At address, you establish specific angles with your spine and your bend from the hips. Maintaining your right knee flex is vital for preserving those angles throughout the backswing. When the right leg straightens, your right hip rises. This lifts your entire upper body, changing your spine angle and pulling you out of posture. From this "taller" position, you have to make a compensation on the downswing to get back to the ball, which almost always leads to inconsistent contact - thin shots, fat shots, and tops.
• It Prevents the Dreaded Sway: A sway is a lateral shift of the hips away from the target in the backswing. It’s a huge power leak and a primary cause of slices. A flexed right knee acts as a brace or an anchor. It encourages your right hip to rotate *back and around* your body rather than sliding sideways. A stable, flexed knee is the best antidote to a sway.

The Two Common Mistakes You're Probably Making

Most issues with the right knee fall into two categories. See if either of these sounds familiar. It’s often a huge "aha!" moment for golfers when they identify their-own pattern.

Mistake #1: The Straight-Leg Lockout

This is by far the most common fault. As the player takes the club back, their right leg progressively straightens until it’s nearly locked out at the top of the swing. Visually, you can see their right hip is much higher than their left.

• What it Feels Like: You might feel like you're making a huge, powerful turn. Weight often shifts to the outside of your right foot, and you feel very tall at the top.
• What it Causes: This move is the classic precursor to a "reverse pivot." Because your right hip has moved up and away, your weight actually falls back onto your left side at the top. Then, on the downswing, you have to lunge forward onto your right side to try to make contact. It reverses the entire proper weight shift sequence. The result is a steep, over-the-top swing path that produces weak fades, ugly slices, and inconsistent strikes.

Mistake #2: The Lateral Sway

In this fault, the knee doesn't necessarily straighten, but the entire right leg and hip unit slide away from the target. Instead of the right hip pocket turning behind you, it slides towards the golfer standing on the tee box next to you.

• What it Feels Like: It often feels like you’re trying to "load" your right side, but the pressure builds heavily on the outside of your right shoelaces. Your head will almost certainly move off the ball.
• What it Causes: A sway completely destroys your ability to create a powerful coil. You’ve just shifted your weight laterally instead of rotating. From this position, it's hard to get your weight back to your front foot in time. You either get "stuck" on your back foot, causing you to scoop at the ball and hit shots thin or fat, or you slide your hips too far forward in the downswing, leading to big blocks and pushes to the right.

The Correct Movement: "Turn, Don't Lift"

So, what’s the right way to do it? The key is to feel like your right knee maintains its flex while your right hip rotates. It’s not a static, locked position. The knee will lose *some* flex as your hip turns - it has to. But it should never feel like it's straightening or locking out fully. The right word for the feeling is a controlled bracing or resistance.

As you start your backswing, your right hip should turn back and away from the target line. Imagine there's a wall behind you, your right hip pocket would turn along that wall, not push away from it. As this happens, your right knee should feel like it's rotating internally, maintaining its flex and position. The pressure should stay on the inside of your right foot or the ball of your foot, not on the outside edge.

Three Drills to Master Your Right Knee Action

Talking about it is one thing, feeling it is everything. Here are three simple drills you can do anywhere to build the correct muscle memory. Start slowly without a ball until the movement feels more natural.

1. The Stick Brace Drill

This is the best drill for providing instant, clear feedback on a sway.

1. Take an alignment stick or a spare golf club and stick it in the ground just outside of your right foot, angled slightly inward to match your knee's address position.
2. Set up to an imaginary ball, letting the outside of your right knee lightly touch the alignment stick.
3. Make slow, deliberate backswings. Your goal is to turn your hips and shoulders while keeping your right knee in contact with the stick. You should feel your hip turning *behind* you while your knee remains relatively still.
4. If you sway, you will immediately feel your knee push hard into the stick. If you straighten your leg, you’ll lose contact with it completely. This drill forces you to rotate around a stable right leg.

2. The Ball Under the Foot Drill

This drill helps you feel how to maintain pressure on the instep of your right foot, training you to resist the urge to roll to the outside or stand up.

1. At address, place a golf ball under the outside edge of your right foot. You should feel a slight inward tilt in your foot.
2. Again, make slow backswings. The objective is to complete your backswing without letting the golf ball shoot out from under your foot.
3. To do this, you have to actively keep pressure on the inside of your right foot as you rotate your hips. It immediately punishes both a sway (which mashes the ball) and a leg-straightening move (where your foot loses pressure and the ball rolls away).

3. The Back-Against-the-Wall Drill

This drill is exceptional for understanding proper hip rotation versus a lateral sway, and it's perfect for practicing at home.

1. Stand about 6 inches from a wall, taking your normal address posture so your behind is lightly touching the wall.
2. Simulate a backswing. As you turn, your right glute and hip should remain in contact with the wall, sliding along it. Your left glute will move away from the wall toward the golf ball.
3. If you sway, you will feel your hip push aggressively into the wall. If you straighten up out of posture (leg straightening), your entire backside will come off the wall. The correct feeling is a smooth rotation where your right hip "traces" the wall as it moves back.

Final Thoughts

Fixing your right knee action boils down to one simple concept: stable legs allow for a powerful, athletic turn. Stop thinking about "restricting" your hips and start thinking about rotating them around a flexed, stable right leg. Master this, and you’ll unlock a sequence that delivers more effortless power, better posture, and striking consistency you've been looking for.

Understanding and fixing a specific swing issue like knee flex is often a case of "feel versus real." You might feel like you're staying in posture, but you can't be sure without an objective look. Instead of guessing, we made it simple to get that feedback. With our on-demand golf coach, Caddie AI, you can capture your swing a get tailored analysis and drills directly to your phone. It’s a way to get a second opinion right on the range, helping you diagnose the root cause of an issue and giving you actionable advice to work on your very next shot.