Face-on
Lead knee at impact.
Lead knee at impact is how the lead knee looks at the strike, compared with the top. A straighter look can describe that change. It is not an instruction to lock the knee.
By Dwain Kinghorn · Updated
Face-on · Pre-Impact, Impact, Follow-Through
Understanding the idea.
Face-on, compare Pre-Impact, Impact, and Follow-Through. At the top the lead knee is often flexed. By the strike it often looks straighter, because the lead side is accepting the swing and the golfer is moving through. That change is what this guide names. The knee you see is the picture. It is not a pose to copy, and it is not a score.
Do not force the knee straight, post it, or snap it as a way to hit the ball. A knee locked before the ball arrives can throw the club outward and leave the joint with no give. A knee that stays very flexed and drifts toward the ball is a different picture, often with a heavy strike. Both are worth seeing. Neither is fixed by locking the leg.
The lead foot and the pelvis do work that the knee's outline does not explain. Video cannot measure pressure under the foot, and it cannot tell a leg that is bracing from a leg that only looks straight because the camera is off to the side. Keep both feet, the lead knee, and the ball in frame so you know which moment is the strike. The clubhead may leave. The ball should not.
Follow-Through tells you whether the golfer kept moving or stalled on a straightened leg. A finish they can hold, with the knee comfortable, says more than a freeze at impact.
How to read this pattern.
Knees differ. Taller golfers, golfers with less bend available, and golfers playing a shorter shot will not show the same outline. Impact does not have to reproduce the address knee. A little straightening as the swing moves through can simply be part of moving through. Locking the knee, or holding it straight as a position to strike from, is the version to avoid.
If the strike is solid and the knee looks quiet, you do not need a knee project. Look here when the knee collapses toward the ball with heavy contact, or when it snaps straight and the strike gets thin or wild.
A practice cue.
Let the club meet the ball and keep traveling through it.
Try the exercise.
Club keeps traveling
Use a mid-iron on turf or a mat where you can see the brush. Set the camera face-on, wide enough for both feet, the lead knee, and the ball. The task is the club. Hit easy shots and let the club keep traveling after the strike, out to a balanced finish.
Do not think about the knee while you swing. After the set, watch Pre-Impact, Impact, and Follow-Through. You are looking for what the knee did when you were busy with the club. If you see that you locked it, the task got replaced. Go back to the club traveling and film again.
If the knee drifts toward the ball and the strike gets heavy, do not answer by snapping the leg straight. Make a smaller swing, keep the club traveling, and look again. One change. Stop if the knee feels pinched or forced.
What to record
On replay only, compare the knee at the top with the knee at the strike. A locked knee is not a successful rep.
Practice set: 2 sets of 6 easy mid-irons, then watch the knee only on replay.
Keep in mind: The club is still traveling at the strike.
Review the result.
For a practice comparison, record 5 full mid-iron swings from a face-on view. Use the same setup for both sets; label shorter drill swings separately.
Record five full mid-iron swings, face-on, with both feet, the lead knee, and the ball visible. Compare the knee at the top with the knee at the strike, and then with the finish. Straighter than the top can be a description. A locked knee is not a success. Video still cannot measure pressure under the foot.
Watch these clips.
These demonstrations offer another way to understand the idea. Each video opens at the selected starting point and continues playing; use the note below it to focus your viewing.
He treats the lead leg as something to push from, and he says the knee stays slightly flexed into the strike. Straightening too early, or hyperextending, throws the club and loads the joint. That matches this guide: do not force the knee straight.
They describe the knees changing jobs from the backswing to impact, including a lead knee that looks straighter than it did at the top. Watch the change. A locked knee is not the assignment, and the trail knee is the other leg.