Early extension: the one-line video check

At address you hinge forward from the hips. Your backside sits out behind you and your spine tilts toward the ball.

In a good downswing, the hips turn and keep roughly that depth. Your backside stays close to where it started, and your chest stays tilted over the ball into impact.

With early extension, the hips thrust forward toward the ball during the downswing. The pelvis moves into the space your arms need, and the torso straightens up to make room. Coaches also call it "losing posture" or "standing up".

From down-the-line it is easy to see once you know where to look. Your backside comes off its starting spot, and your head often rises too.

You need a down-the-line video: camera behind you at hand height, pointing along your hand line toward the target. The filming guide has the details. Don't move the phone between swings, or the line stops meaning anything.

1. Pause on the address frame.
2. Draw a vertical line that just touches the back of your backside. Run it from the ground up past your waist.
3. Set playback to 0.25x and step frame by frame to impact.
4. Look at the gap between your backside and the line.

What you will see:

• Backside still touching the line, or close to it: you kept your depth.
• A clear gap, with the hips moved toward the ball: that's early extension.

Check your head too. If it has risen compared with address, your torso has probably stood up along with the hips.

For a second view, draw a line up your spine at address (tailbone to the base of the neck) and compare its angle at impact. If it's more upright at impact, you've lost posture.

When the hips move toward the ball, your arms and the club have less room. The body has to find a way to get the club back to the ball, and that usually shows up as one of these:

• Thin shots. As you stand up, the club rises with you, so the leading edge catches the ball low on the face.
• Blocks. The hands get stuck in front of the body and the clubface stays open, so the ball goes right for a right-hander.
• Hooks. To square a face that's been left behind, the hands flip over hard through impact.
• Shanks. Hips moving toward the ball can push the hands out, so the hosel reaches the ball first.

Not every one of these comes from early extension, but if you see two or three of them in the same round, it's worth running the one-line test.

Mobility

Turning the hips through the downswing while keeping your forward bend takes some hip and trunk rotation. If your body can't rotate there, it often finds the movement by thrusting forward instead. A golf fitness coach or physio can test this properly.

Setup

A poor address position makes early extension more likely:

• Standing too upright, with little hip hinge, gives the hips nowhere to stay back from.
• Weight sitting on the toes tends to pull you toward the ball.
• Standing too close to the ball leaves the arms crowded from the start.

Downswing sequence

If the arms and shoulders start the downswing, the club can get steep or outside, and the body often stands up to make room for it. That's why early extension and over the top can appear in the same swing. Fixing one sometimes helps the other.

This is the classic early extension drill and you can do it at home without a ball.

1. Set up with your backside just touching a wall, or the back of a chair.
2. Make slow swings to the top. Your trail side of the backside should stay in contact.
3. Swing down to impact. Feel the lead side of your backside move back to touch the wall as you turn through.
4. If your backside comes off the wall toward the ball before impact, that's the fault.

Start at half speed. Once it feels natural, take the feeling to the range and hit balls with the same thought.

Re-film and re-check. Film down-the-line from the same camera spot, draw the same vertical line at address, and step to impact. Compare the gap with your first video.

If your address is off, the swing has to fix it on the fly. Sort the setup first.

1. Hold a club vertically along your spine, touching your tailbone, upper back and the back of your head.
2. Hinge forward from the hips, keeping all three points on the club. Push your backside back as you go.
3. Let your knees flex slightly and your arms hang straight down from the shoulders.
4. Check your weight sits roughly over the middle of your feet, not the toes.

That's your address posture. Rehearse it a few times before you hit balls.

Re-film and re-check. Film a swing from down-the-line and pause on address. Draw a line up your spine and compare it with an older swing. Then run the one-line test to impact.

Impact is the frame where early extension shows most clearly, so that's the one to analyze.

1. Step to the frame where the club meets the ball.
2. Tap AI on mobile or AI Coach on desktop, then Analyze Current Frame.
3. You get back the swing phase, up to three strengths, up to two fixes and one drill.

The AI only sees that one frame, so it can't compare it with your address position. Your backside line does that job. Use the two together: the line tells you how much you moved, and the AI gives a second opinion on posture and a drill to try. Only the paused frame is sent; your video stays on your device.

Practise the line test on a reference swing first. Open the Tiger Woods iron sample and scrub to a down-the-line swing (camera behind him, looking at the target; from about the two-minute mark it is the right half of the split screen). Pause on address, draw a vertical line on his backside, then step to impact and see how much the hips have moved.

Then run the same test on your own swing. The compare to a pro guide shows how to match up the same checkpoints between two swings, and the full swing analysis guide covers the other checkpoints.