Here's what you need to know...

  1. Setting up the ab crunch machine in a less than optimal position can create brutal and inefficient force planes, which increases the chance of injury.
  2. By determining the best setup for your body type, the crunch machine can go from a potentially debilitating movement to a results-producing method.
  3. Using the back extension machine isn't that much different from picking up a heavy object with a horribly rounded-back.
  4. Hip adductor and abductor machines are a scam. The lateral lunge is better and safer.
  5. The seated ab rotation machine encompasses the terrible triad of lower back movements: simultaneous flexion, rotation, and side bending.

Here are four commercial gym machines that you should avoid at all costs, ranked from least horrible to most horrible.

4 – Seated Ab Crunch Machine

Ab Crunch Machine

The ab crunch machine brings together two American novelties – the idea of achieving a chiseled six-pack and doing it while slouched over on your ass watching Whoopi drop opinion bombs on The View.

Whether you're for or against training the spinal column into relative flexion, this machine unites all core-training schools of thought in its blatant disregard for what intelligent movement methods should actually entail.

Primary Problem:  Unsafe Setup

When was the last time you exerted a concentrated effort to set the machine up according to your specific anthropometrics?

It's safe to say that unless the setting on the machine is physically causing him pain while he's doing it, the average gym goer will power through his sets just fast enough to hightail it to the next exercise.

The ab crunch machine is no different than any other machine, but setting up in a less than optimal position can create some pretty brutal and inefficient force planes.

These unwanted forces could increase the chance of injury, especially when used with exceptionally high rep ranges and frequencies, as people have been known to do with core training movements.

When setting up in a relatively forward-flexed starting position at the spine and pelvis, as opposed to being slightly extended (as is usually preferred by the spinal column), the only way you can train is by going into hyper-flexion of the spine, which can play a role in a number of types of lower back pains and dysfunctions.

Before you write off this machine for good, though, check yourself, literally. By spending an extra few seconds to determine the most advantageous setup for your specific body type, the crunch machine can go from a potentially debilitating movement to a results-producing method for abdominal training:

  1. Sit your hips back as far as possible into both the back pad and seat pad. Sitting back will center your ass and pelvis in the seat and reduce the likelihood of any unwanted pelvic shifting during the dynamic movement.
  2. Position the abdominal pad just below the level of your sternum to create the right length lever arm.
  3. Last, but not least, your starting spinal position should be in slight extension. Though this position is unique to every body type, you can find it by first getting yourself into neutral posture and then arching your thoracic and upper lumbar spine slightly.

Alternative:  Standing or Kneeling Banded Crunch

Banded Crunch 1
Banded Crunch 2

This movement will incorporate accommodating resistance to overload your rectus abdominis with a fraction of the external load while training your abdominal group to work from a neutral pelvic position.

3 – Seated Back Extension Machine

Back Extension Machine

Have you ever wondered about the true origins of the lower back pain experienced by nearly 80% of Americans at some time or another?

No, I'm not going to blame seated back extensions for this grotesque number, but I will attribute a majority of that ever-climbing statistic to the lack of spinal postural awareness in the gym, in daily life, and beyond.

This is a real problem that's getting worse, and machines like the back extension aren't doing our society any favors.

Primary Problem:  Structural Spinal Insult

Back Pain

Using the back extension machine isn't that much different, biomechanically speaking, than picking a heavy object up off the ground with the most dysfunctionally heinous rounded-back form you can imagine.

Imagine a really ugly barbell-loaded good morning movement with the knees locked out, the hips not translating backwards, and the majority of the stress going right through the lower lumbar segments as the movement comes back into a neutral position.

No one with any hopes of walking without a permanent limp for the rest of their life would be caught dead loading up this type of dysfunctional movement pattern, but that's essentially what many people are doing when loading up heavy on the back extension machine.

In order to generate any movement whatsoever out of the seated starting position, most back extension machines require that the thoracic and lumbar segments must start out in a forward flexed position to increase the available range of motion.

It's important to remember that in the seated position, the available range of motion of the spine is largely limited compared to the fairly large range available when the hips move in conjunction with the spine.

You know what's not limited in a seated position? Spinal flexion. When using the back extension machine to target the spinal extensor groups that run from the tailbone all the way into the skull, a majority of the movement requires moving from a hyper-flexed position to a neutral spinal orientation, if you're lucky.

Most people realistically never break past a neutral spinal position at peak contraction, making this machine not only potentially dangerous when executed like shit with no rhyme or reason, but also highly inefficient when targeting the large slabs of muscle responsible for extending and stabilizing the spine.

Alternative:  Banded Hyperextension

Banded Hyper 1
Banded Hyper 2

There are safer and far more effective programming options out there. It's safe to say that you could literally program any type of back extension movement into your routine and achieve far better results than the back machine while not crunching your spinal structure.

However, for the most translatable strength and hypertrophy gains in the spinal extensors, be sure to utilize spinal extension movements that incorporate terminal hip extension like the banded hyperextension in the 45-degree Roman chair.

Not only will your erectors get a massive pump from the accommodating resistance, your glutes and proximal hamstrings will also aid the movement, helping this assistance movement fuel your big lifts.

2 – Seated Hip Abductor/Adductor Machine

Adductor Machine

Machine manufacturers really threw away any semblance of moral or ethical practice with the widespread and continued production of hip adductor and abductor machines.

Preying on the insecurities of uninformed and vulnerable women is a staple of dirtbags in any field, but when it hits the fitness industry I tend to take it more personally.

Primary Problem:  Intentions of Scamming

No matter how many times the deeply rooted belief of spot fat reduction is debunked with scientific research and millions of walking, talking anecdotal cases, this disturbingly misleading misconception keeps coming back like the zombie apocalypse.

Though everyone has their own specific pockets of stubborn body fat, one troubled area for many people is the thighs. But no matter how intense these movements are trained, nothing really ends up happening in terms of body recomposition, except for developing some seriously strong hips for leg wrestling and other things.

Along with lack of fat loss around the inner thigh and lateral hips, the functionality of these machines is pretty atrocious unless you're an experienced strength athlete with acute hypertrophy as a goal.

The gluteal group, which most people attempt to target when using the hip abductor machine, is actually placed in an insufficient position to carry out its primary actions of hip extension and abduction.

Generally speaking, when targeting a muscle group, the plane of movement needs to match up with the fiber orientation of the muscle. When these two variables don't match up, it's open season for secondary compensatory muscles to take over the movement, thus losing all hopes of targeted results.

It gets worse. Want to tighten down your IT-band complex even more than it already is from sitting at your desk eight-plus hours a day? Hit up the hip abductor machine on a regular basis.

The tensor fascia lata, the muscle that directly attaches proximally to the IT-band, will become over active during the seated hip abduction movement, causing an entire chain of potential problems down the line.

Very similar to its counterpart, the hip adductor machine places the targeted hip adductors and medial hamstring group at a biomechanical disadvantage.

Because a majority of these muscles attach to the pelvis, malalignment occurs when placed in a seated position, decreasing the likelihood of targeting this muscle group with any hopes of results.

Alternative:  Lateral Lunge

Lateral Lunge 1
Lateral Lunge 2

Skip the seated hip adductor and abductor machines. If your goal is to target the lateral hip musculature while also incorporating the adductor and medial hamstring groups in a loaded movement, you can kill two birds with one stone with the lateral lunge.

Not only does the lateral lunge load the lateral-hip stabilizing gluteal group through a larger range of motion at the hip than the machine, the adductor group is tensioned under eccentric loading, which is great for hypertrophy and translatable strength.

1 – Seated Ab Rotation Machine

Ab Rotation

In the first two semesters of physical therapy school, a portion of the curriculum includes the foundations of biomechanics and ways to translate these properties into the real world.

The one point that was absolutely nailed down over the course of that year was avoiding the worst possible situation for the longevity and health of the lumbar spine. Above all else, avoid moving through the terrible triad of lower back movements: simultaneous flexion, rotation, and side bending, especially under loading.

In other words, avoid the seated ab rotation machine!

Primary Problem:  Everything

The seated ab rotation machine superficially seems to have some merit in core training due to the rotational component that supposedly targets the internal and external obliques on opposite sides simultaneously.

Unfortunately, everything from positioning to safety, efficacy, and effectiveness is wrong with this abominable waste of space.

It should be clear by now that the staple seated position that's been mentioned multiple times on this dirty list of the worst exercise machines known to man isn't advantageous for your aesthetics or your general orthopedic health.

More specific to the ab rotation machine, the force plains just don't match up (again). Sound familiar? The internal and external obliques encompass the anterior and posterior lateral trunk attaching to multiple sites throughout their large surface area and distribution.

The internal and external obliques are adjacent layers of core musculature that are positioned in a relatively perpendicular orientation to each other. This orientation doesn't include being horizontal for either of these two muscles.

In order to target the obliques in this machine, spinal flexion must be incorporated into the movement. (Remember that thing about the terrible triad of positioning for lower back health?)

If you want to argue that this dynamic rotational movement targets the deepest layer of the abdominal wall, think again. Though the transversus abdominis fiber orientation is indeed horizontal in position, this muscle is responsible for tonic contractions, meaning it wouldn't be optimally activated or stimulated for functional or aesthetic purposes during the violent rotations afforded by this machine.

Finally, the amortization phase of this movement creates a slippery slope for both soft tissue and structural spinal health. Amortization is the phase between the eccentric and concentric contractions and is usually largely dependent on fine neurological functioning.

But when cranking out rep after rep on the ab rotation machine, you're actually frying the neural system that would normally stabilize the spine properly. You then lose the dynamic stabilization your spinal segments and core need to protect themselves against the external load.

It should probably go without saying to skip this machine.

Alternative:  Pallof Press

Pallof Press 1
Pallof Press 2

Want to target the entire core, including the shoulder and hip complexes in addition to the abdominal wall? Give the Pallof press a shot. This anti-rotation movement will challenge your static and dynamic stability of the pillar all at once.

Think it looks too easy? Load it up and don't budge an inch except for controlling your arms in a smoothly coordinated manner. The internal tension you'll be able to achieve will sky rocket your heart rate, burn your core, and make you wish you were back on the ab rotation machine.

Related:  The 4 Most Debilitating Exercises

Related:  The 4 Dumbest Ab Exercises