Jammer arms add guided pressing and pulling movements to a compatible power rack. Each arm pivots around a fixed mounting point, creating a repeatable movement arc that feels different from training with a barbell or dumbbells.
Their versatility comes from the setup. Changing the arm height, starting angle, handles or stance can turn the same pair of jammer arms into a chest press, shoulder press, row or unilateral strength exercise. With the right attachments, a rack can cover several movements that would otherwise require separate plate loaded machines.
What are jammer arms?
Jammer arms are adjustable lever arms mounted to a compatible rack or rig. They pivot around a fixed point and can be plate loaded when suitable weight loading pins are fitted.
The term "lever arms" is also used for this type of equipment, although "jammer arms" is the clearer strength training term.
The fixed pivot guides the movement through a defined arc. The lifter still controls body position, force production, grip and range of motion. This makes jammer arms useful for repeatable accessory work while retaining more setup freedom than many fixed machines.
How to use jammer arms
The most important setup variables are arm height, starting angle, grip and stance position.
For a chest press, the handles should begin around a comfortable pressing height. Raising the starting point shifts the movement towards a more shoulder dominant press. Lower positions work better for rows and other pulling movements.
Angle adjustment is equally important. A small change in the starting angle changes where the resistance is felt during the repetition and how much usable range of motion is available.
A simple setup process works for most exercises:
- Position the arms at the required height.
- Set the starting angle for the movement.
- Fit the handles or attachment.
- Check that all pins and connections are fully secured.
- Test the exercise with a light load.
- Adjust your stance until the starting position and movement arc feel controlled.
- Add load once the setup is repeatable.
The Riot MRR 75 Jammer Arms with Multi-Grip Handles and Weight Loading Pins provide the core setup for plate loaded jammer arm training.
Jammer arm exercises
Jammer arm chest press
The chest press is one of the easiest movements to set up with jammer arms.
Position the handles around chest height and adjust your stance so you can begin the press from a controlled position with a comfortable range of motion. Press forwards through the arc while keeping the torso stable and the shoulders controlled.
A slightly lower start tends to keep more emphasis on horizontal pressing. Raising the arms changes the pressing angle and increases the contribution of the shoulders.
The exercise mainly trains the chest, triceps and anterior deltoids. The upper back and trunk help maintain position throughout the set.
Multi-Grip Handles make it possible to adjust hand position according to the preferred elbow and shoulder path.
Jammer arm shoulder press
For a shoulder press, move the starting position higher and choose an angle that allows the handles to travel upwards while the shoulders remain controlled.
Stand with a stable base and press upwards and forwards along the lever path. Keep the ribs and pelvis controlled instead of compensating with excessive backward lean.
The fixed arc gives the movement a different feel from a barbell overhead press, making it useful as an additional shoulder and triceps exercise.
Jammer arm row
For rowing movements, position the arms lower on the rack.
Choose a stance that creates tension at the beginning of the repetition while allowing the torso to remain controlled, then pull the handles towards the body. The body angle and elbow path determine where the exercise places most of its emphasis.
Keeping the elbows closer to the body generally increases lat involvement. A wider elbow path brings more of the upper back and rear deltoids into the movement.
Once the height and stance are set, the same position can be reproduced easily across several working sets.
Unilateral jammer arm press
Independent handles allow one arm to work at a time.
A unilateral press creates an asymmetric load, increasing the demand on the trunk while allowing each side to produce force independently. It can be useful for additional single side volume or for identifying differences between left and right.
The Riot MRR 75 ISO Bar Handles suit this type of setup particularly well.
Keep the stance and body position consistent between sides so that the working arm remains the main variable.
Unilateral jammer arm row
The same independent setup works well for rowing.
Set the arm low enough to create tension in the starting position and pull towards the ribs or hip according to the intended back emphasis.
Training each side separately makes it easier to keep the movement controlled and prevents the stronger side from taking over a bilateral repetition.
Bilateral presses with a Straightbar
Connecting both arms creates a different style of movement.
The Riot MRR 75 Straightbar links both jammer arms into a single grip position. This works well for bilateral chest pressing, shoulder pressing and other movements where both hands should work together.
The fixed bar also makes hand spacing easy to reproduce between sets.
Jammer arm attachments and what they change
The jammer arms provide the lever system. The attachment determines how force is transferred into it.
Multi-Grip Handles
Multi-Grip Handles provide several hand positions for pressing and pulling.
Changing the grip alters wrist position, elbow tracking and shoulder rotation. They are a versatile option when the same setup is used for several different exercises.
ISO Bar Handles
The ISO Bar Handles allow each arm to move independently.
They suit unilateral presses, single arm work and alternating repetitions particularly well.
Straightbar
The Straightbar attachment connects the two sides.
It is useful for bilateral movements where a consistent two handed grip is preferred.
Landmine attachment
The Riot MRR 75 Landmine attachment adds landmine movements to the rack setup.
Landmine exercises use their own movement path and technique, so the subject is kept separate here. The dedicated Landmine Press guide covers setup, muscles worked and useful variations in more detail.
Which attachment suits which training goal?
| Training goal | Useful setup |
|---|---|
| Chest pressing | Multi-Grip Handles or Straightbar |
| Shoulder pressing | Multi-Grip Handles, ISO Bar Handles or Straightbar |
| Independent left and right side work | ISO Bar Handles |
| Bilateral pressing | Straightbar or Multi-Grip Handles |
| Unilateral rows | ISO Bar Handles |
| Multiple grip positions | Multi-Grip Handles |
| Landmine exercises | Landmine attachment |
| Plate loaded training | Jammer Arms with Weight Loading Pins |
The best choice depends on the exercises that need to fit into the programme. A lifter using frequent unilateral work needs a different setup from someone mainly looking for bilateral accessory pressing.
Power rack jammer arms in a home gym
Jammer arms are particularly useful when the power rack already forms the centre of the training space.
Compatible attachments can expand the number of movements available around the same structure. The Riot MRR Components and Add-ons and Rig & Rack Add-ons provide further options for building around a rack based setup.
Height and angle adjustment also make it possible to change exercises without dedicating a fixed station to one movement. Once useful positions have been established, they can be repeated consistently during later sessions.
Compatibility should always be checked before combining rack components and attachments.
For smaller training spaces, the rack can become the central structure around which the rest of the equipment is organised. The guide to building a home gym for small spaces covers that subject in more detail.
Are jammer arms worth it?
Jammer arms are most useful when the additional exercises fit the training programme.
For a rack based home gym or training space, they can add repeatable chest presses, shoulder presses, rows and unilateral movements while using the same main structure. Different handles then change how those movements are performed.
A powerlifter focused mainly on the competition lifts may use jammer arms primarily for accessory work. A home gym designed around a broader mix of strength and functional training can make much more frequent use of them.
The practical starting point is the exercise list. Decide which movements the rack should provide, then choose the handles and attachments that support those movements.
FAQ
What muscles do jammer arms work?
The muscles depend on the exercise. Pressing movements mainly involve the chest, shoulders and triceps. Rows train the lats, upper back, rear deltoids and elbow flexors. Unilateral variations also increase the stabilisation demand on the trunk.
Can you plate load jammer arms?
Yes, when the system uses suitable weight loading pins. The Riot MRR 75 Jammer Arms setup includes weight loading pins for plate loaded training.
Are jammer arms the same as lever arms?
The terms are often used for the same type of strength equipment. "Jammer arms" is the more specific term for rack mounted lever arms used for pressing, pulling and similar exercises.
Which jammer arm attachment should I choose?
Choose according to the movements in the programme. ISO Bar Handles suit independent arm work, the Straightbar connects both sides, Multi-Grip Handles provide several grip positions, and the Landmine attachment adds dedicated landmine exercises.