Stop Straightening Your Trail Arm: Sidearm Throw Drill

This drill teaches you how to keep your trail arm connected to your pivot instead of straightening it too early through impact. If you tend to stand up, thrust your hips toward the ball, or feel like you have to “throw” the clubhead down to reach the ground, this is a useful training piece. The goal is to blend a sidearm-throw motion with a one-arm strike so you learn how the body swings the arm, not the other way around. When you do it correctly, your trail arm stays more in front of your torso, your posture is easier to maintain, and impact starts to feel much more rotary and controlled.

How the Drill Works

The drill combines two ideas. First, the sidearm throw gives you the motion pattern: your body stays inclined, your torso keeps rotating, and your trail arm works more around you rather than immediately straightening toward the ball. Second, the trail-arm-only shot adds a strike so you can turn that motion into something functional.

To set it up, place a driver or alignment barrier on the ground so it sits roughly even with your lead foot. This object gives you a spatial reference. When you rehearse the motion, you will feel as if you are making a sidearm throw underneath that shaft while staying in your golf posture. That image helps you keep your chest inclined and discourages the common move of standing up through the shot.

From there, use a short or mid iron—something like a 7- or 8-iron is a good starting point—and hit small shots with only your trail arm on the club. The key sensation is that your arm is not independently firing past your body. Instead, your pivot carries the arm through. The club is moving on a more compatible plane with your torso rotation, so you no longer need a last-second dump or thrust to get the clubhead to the ball.

This is especially helpful if your shoulders tend to turn too level in the downswing. When that happens, the club often gets too high and too far from the proper delivery path, and your instinct is to straighten the trail arm early just to get the club down. The sidearm-throw feel changes that. It encourages a more natural blend of side bend, rotation, and arm motion so the club can approach the ball without you having to rescue it.

Step-by-Step

Set a barrier by your lead foot. Lay a driver or similar club on the ground so it is roughly even with your lead foot. This is not something you are trying to hit. It is simply there to shape the motion and give you a visual for the sidearm throw.
Take your normal golf posture. Bend from the hips and let your chest stay over the ball. You should feel athletic and balanced, with enough inclination that it would be difficult to stand up without noticing it.
Rehearse the sidearm throw without a ball. Using your trail arm, make a small throwing motion underneath the shaft on the ground. The feeling is not overhand and not straight at the ball. It is more of a low, sidearm delivery while your body keeps rotating.
Notice your torso position. In a good rehearsal, you will feel as if you stay bent over and keep your chest working around. Many players describe it as feeling like they are almost looking underneath their trail arm as they move through.
Switch to a trail-arm-only swing. Take your 7- or 8-iron and grip it with only your trail hand. Start with very small swings. You are not trying to hit full shots yet.
Make a short backswing and rotate through. Bring the club back a short distance, then turn through while keeping the trail arm in front of your body. Let the body motion move the arm and club through impact.
Hit soft, controlled shots. The strike should feel more like a body-driven hit than a handsy slap. If the motion is correct, the club will reach the ball without you needing to forcefully straighten the trail arm.
Check your finish. After the strike, pause and look at where the club finished. Ideally, the club should still be out in front of your torso. Your chest should be rotating through, not facing the ball while the arm has flung across your body.
Repeat until you find a solid one. You may hit a few thin shots at first if you revert to throwing the arm. When you catch one solidly with the club staying connected to your body turn, stop and memorize that finish position.
Hold the finish for 15 to 20 seconds. Step away from the barrier if you want, look back at the ball, and rehearse that same through-swing position. This helps your body absorb the correct alignments instead of immediately moving on to the next ball.
Build into bigger swings. Start with 9-to-3 swings, then progress to 10-to-2 or three-quarter swings. Once the motion is stable, blend the same feel into your full swing.

What You Should Feel

The biggest feel is that your trail arm is being transported by your pivot. It is still active, but it is not taking over. If you are used to driving the club down with your right side, this will probably feel much quieter and much more connected.

Key sensations

Your chest stays inclined instead of popping up through impact.
Your trail arm stays in front of you rather than firing out and across your body.
Your body keeps turning so the club can keep moving left with your pivot.
The club reaches the ball because of rotation and structure, not because you desperately straighten the arm.
Impact feels compressed and shallow, not slapped or dumped.

You may also notice that the motion feels as if your arm and body are working on a more similar angle. That is important. Many players who early extend have a mismatch: the torso works too level, then the arm has to work too vertically and too forcefully to recover. This drill helps bring those pieces back into sync.

Checkpoint at the finish

Your best checkpoint is the follow-through. If the drill is working, your body will be rotating and the club will appear in front of your torso in the finish. If your chest stalls and the club wraps far across you, the arm took over.

A good finish usually includes:

Your torso more open than it was at address
Your posture largely maintained
The club traveling with your body turn, not past it
A sense that the strike was produced by motion through, not a hit at the ball

Common Mistakes to Avoid

Straightening the trail arm too soon. This is the very pattern the drill is trying to fix. If you feel a hard shove with the trail hand before your body has rotated, slow down and shorten the swing.
Standing up through impact. If your pelvis moves toward the ball and your chest rises, you will lose the sidearm feel. Stay in your posture and let rotation happen around that inclination.
Throwing the arm across your body. Some players avoid standing up, but then simply sling the arm left with no body support. The club should not race past your torso.
Turning the shoulders too level. A flat shoulder turn often forces the arms to reroute aggressively. Let the motion feel more angled and more compatible with your golf posture.
Starting with too much speed. This drill is about patterning, not power. If you go too fast, your old compensation will usually return.
Using too much club. Start with a shorter iron. A long iron or driver can make it much harder to organize the motion.
Ignoring the finish position. The finish tells you whether the body or the arm dominated the strike. Always check it.
Trying to hit down by force. You do not need to shove the handle or smash the club into the turf. Let the pivot deliver the club naturally.

How This Fits Your Swing

This drill is not just about your trail arm. It is really a drill for improving the relationship between your pivot, posture, and arm delivery. If you early extend, get stuck, or feel like you have to save the shot with your hands, there is a good chance your body and arms are no longer working together through the strike. This exercise restores that connection.

In the bigger picture, the drill helps you understand a central concept in good ball striking: the body swings the arm. That does not mean your arms are passive. It means they are organized by the motion of your torso, not acting independently in a way that forces compensations. When your body keeps turning and your posture stays stable, the trail arm can extend at the proper time instead of too early.

It also gives you a practical bridge from rehearsal to real golf shots. The sidearm throw by itself is a useful feel, but the one-arm strike makes it playable. You are not just mimicking a movement in the air—you are learning to hit a ball while preserving the same geometry. That is what makes this drill valuable on the range.

A smart progression looks like this:

Start with slow rehearsals of the sidearm throw
Move to trail-arm-only 9-to-3 shots
Build to three-quarter swings
Blend the same through-swing feel into your normal two-handed motion

As you transition into full swings, do not chase the exact same exaggerated sensation. Instead, keep the core ideas:

Your posture remains intact
Your pivot continues through the ball
Your trail arm does not dominate the delivery
Your club stays in front of your body through the strike

If you can carry those pieces into your stock swing, you will usually see better contact, less early extension, and a through-swing that looks and feels far more efficient. The shot starts to come from a rotating body with a connected arm motion instead of a late, desperate throw of the trail side.