We had a really good question the other day in our member’s platform The Academy that we thought warranted a detailed explanation.

“This may be a silly question, but if someone’s hyper mobile should they still lock joints on exercises? On the Beighton screen I score on the knee and elbow extension, and can usually get my palms on the floor, although it’s not from hamstring flexibility as if I keep neutral spine that isn’t great. Hand tests I don’t show positive. My instinct is not to lock, but is this just as that’s what I’ve been told up until now? As surely a lot of gymnasts are hyper mobile, and they must lock out?

I’m thinking specifically the elbows, so handstand etc.”


Ok so first off, it’s definitely not a silly question and one that absolutely warrants further discussion.

So to start with, lets clear up something about the terms extension, hyperextension, hypermobile and under extension. 

In an otherwise healthy joint, the “lock” is simply the natural end range of motion. This signifies a complete opening on one side and closing on the other. All joints should be able to experience their full biomechanical range of motion. This means they should be able to achieve a lock. If they can’t this is something we’d definitely want to address.


Locked joint positions should be extremely strong and extremely stable, much more so than in a bent position. For example, if you were to unlock your knees and stand around for a significant amount of time with bent legs you’re going to get pretty fatigued.

Isometrically locking your joints with appropriate load and leverage is also FANTASTIC at developing the strength of the connective tissue.

  • Hyperextension is where a joint travels past the physiological ‘norm’ for a particular range of motion. Most of the time this only happens during an injurious event involving high speed, impact and a generally bad afternoon or in those individuals who are clinically hyper mobile or potentially suffer specific autoimmune conditions or other disease states that reduce kinaesthetic awareness, ligament tension etc – that’s not most people. What the vast majority of people consider hyper extension is actually in fact just a normal range of motion.

Please note that the term hyper-mobile is not an interchangeable term with hyper-extension. Hyperextension is not a common occurrence.

Hyper extension is where a joint travels past the physiological ‘norm’ for a particular range of motion. Most of the time this only happens during an injurious event involving high speed or impact

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Thou Shalt Not Lock!

One analogy I’ve heard thrown around in the anti-locking circles is…

“Would you ever jump up and land without bending your knees a little bit? No. Instinctively you bend them because it is the best way to deal with resistance and avoid injury. Think of this when trying to remind yourself not to lock your joints during exercise.”

Now this may seem to make sense at first but it’s not factoring in the context of the different movements.

One is dynamic, and the handstand in the question at the start of the article is isometric. 

Of course you don’t want to lock out your knees when you land a jump. You’d be putting a lot of force on your joints if you did. But think about most traditional exercises and think about what force actually is. 

In physics, Force = mass x acceleration.

So unless you’re throwing the weight up and catching it, or doing something awesome like this

You’re not putting a whole lot of force through your joints by locking out in a handstand if there is no acceleration in the mass towards your joint.

But, but, but…

“But I can’t lock my elbows and I’m weak in that position and it doesn’t feel secure or safe”

Of course you can’t if you haven’t been training/practicing straight arm strength!

This is that old chestnut the S.A.I.D Principle. Specific Adaptation to Implied Demand. If you’ve never trained straight arm strength then of course the position is going to be weak. You haven’t conditioned the connective tissue to be able to bear the load/angle etc.

  • As with any training you’re going to have to regress or progress movements to suit your or your client’s specific requirements.
  • Your actin and myosin chains are only accustomed to working through a shortened and incomplete range of motion. Right now you don’t have the proprioceptive mapping to allow the joints to straighten.
  • Initially the poor interdigitation of said actin and myosin chains creates weakness. Please refer back to points 1 & 2

Unfortunately a lot of the information propagated in the health and fitness industry, especially at the foundation levels of education is based on weight training techniques designed for the sole pursuit of enhanced glycogen storage. To put it another way; body-building.

This ironically has very little to do with ‘health & fitness’, it has rather a lot to do with glycogen storage. Granted, not locking out your joints on a sub maximal repetitive movement such as a bicep curl will most likely maintain greater tension on the muscle belly than allowing the joint to complete it’s natural range of motion and lock.. But who cares?

If you want healthy joints move them through as varied and as complex a range as you can possibly dream up. Obviously using common sense and experience to determine what your client’s current ability level can handle

Straightening the arms and holding isometric positions for progressively increased durations and through more challenging leverages will strengthen your tendons, ligaments and aponeurosis to levels that are otherwise unobtainable with classic weight training techniques

Depending on a persons individual biomechanics; level of mobility etc, full extension or a ‘joint lock’ can look very different. In a healthy individual these are all acceptable and safe ranges of motion.

Isometrics are difficult, strength building, stability improving, structure improving, range of motion improving beasts, hence they’re worthwhile pursuing!!

In specific response to the question above if you’re considered hyper-mobile by the beighton scale or any other type of movement screen, then isometrics are even more important for you to spend time developing if you really want that connective tissue to support your joints in a range of different positions.

Practicing straight arm strength is humbling at first. There needs to be some checking-in of the ego which is a magical and highly recommended process as it will open up the body and mind to a whole host of activities that truly are pursuits of health and fitness. 

Summary :

Being able to straighten the elbows or knees completely should be a normal thing but being extremely strong in this position is something that takes training and patience. 2yrs ago I couldn’t completely straighten my arms, no matter how hard i tried. There were a few little pains and grumbles along the way but that was just my neurophysiology flagging the unfamiliarity of the new positions I was pursuing. Now my arms hang straight and I can load my body weight through locked out joint positions with ease. My structure, the stuff that holds my skeleton together is much, much stronger.

If you are otherwise Asymptomatic and want to pursue movement work over classical pumping pursuits, welcome to the other side and get practicing. Those flexed joint positions will straighten out in time!