Are deadlifts Bad for You? 

With so many injuries associated with them, the question has to be asked: are deadlifts bad for you? The short answer is yes - simply because they're done with an over-arched back.

Safe deadlifts are all about getting the spinal biomechanics right.  They're about best posture when super-loading  the spine and not putting muscles and ligaments to disadvantage. When lifting, it's critically important to have maximum tension from the spinal ligaments and optimal line of pull of the muscles to get maximum strength. 

But because teaching techniques emphasise over-arching the back - putting the ligaments on the slack and the  muscles into inner range - they are hurtling  you towards trouble. Too often deadlifts hurt or cause damage and this is why. 

Traumatic Incremental Shear of the Spinal Segments Under Load is Why Deadlifts Are Bad for You

In part, the question 'are deadlifts bad for you' is answered on the page The Correct Way To Do Deadlifts where a simple outline of spinal anatomy clarifies the picture.  

In short, spinal posture has a direct effect on spinal stability (and therefore spinal safety).  It affects the pressure within the intervertebral discs and the efficacy to the holding structures - namely the ligaments and muscles. . A lumbar spine in extension (arched) is less stable and more prone to mishap. A neutral or slightly flexed posture makes everything more secure - the discs more pressurised, better holding tension of the soft tissue structures  - so no errant shear can zap you as you take the load. So you don't 'rick' your back. 

Are deadlifts bad for you? YES, if you do them with an over-arched back. Besides... anything that looks this bad (read awkward and totally unnatural... and much more difficult to do!) usually is this bad.

Deadlifts Are Not Bad for You if You Adopt a Neutral or Slightly Flexed (Bent) Lumbar Spine

• Invokes optimal pressure (primes) the intervertebral disc = stable
  
  
• Reduces loading of the fragile lumbar facet joints = stable
  
  
• Invokes maximum tensile strength from the spinal ligaments = stable
  
  
• Puts the long spinal muscles (erector spinae) on the stretch = stable 
  
  
• Puts the deep spinal muscles (multifidus) on the stretch = stable
  
  
• Makes it easier to get a strong contraction of the abs to pull the belly in = stable
  
  
• Makes it easier to switch on the pelvic floor
  
  
• Makes it easier to reach down to the bar!

Are Deadlifts Bad for You? No, Not if You Invoke the Help of the Powerful Spinal Ligaments

Are deadlifts bad for you? NO, not if you lift with a neutral or slightly flexed lumbar spine, making it more stable and stronger. (It's also so much easier to lift this way!)

The spine's muscles and ligaments play a critically important role in lifting. A low back in neutral or slightly flexed also optimises the function of the core muscles and the stupendously powerful 'posterior ligamentous lock'. Conversely, an over-arched lower back makes it harder to reef the belly in and partially disables the posterior ligamentous lock by putting it on the slack. 

A spine in neutral when lifting, or better still slightly bent (flexed) gets better performance from all the important players: the lumbar intervertebral discs, the spinal muscles and the ligaments.

The spinal ligaments of the low back are hugely strong. Like all ligaments, they connect bone to bone and derive strength from their tension when pulled taut. The low back has six different sets of ligaments arranged in serried ranks from the outside in.  

Six different sets of ligaments (the posterior ligamentous lock) control the spine bending forward. All ligaments work best under tension. The spine bent puts these ligaments on the stretch.

A ligament without tension is useless. The spinal ligaments are stronger when stretched around a rounded (and therefore longer) lower back. The graphic here also shows the anterior longitudinal ligament (far left) the only one restraining the much less useful backward bending action that we rarely employ (except going under the limbo bar!). 

The strongest and most superficial (near the surface) ligament of the back is then super-ligament, the 'X' shaped thoraco-lumbar fascia, shown here (top left). The upper flanks of the fascia are tensioned by the strongest arm muscle (latissimus dorsi) and the lower by the strongest leg muscles (gluteus maximus). The deepest abdominal muscle (transversus abdominis) tensions it laterally through the middle.  It's a wonderful system!

Are Deadlifts Bad for You? No, Not if You Invoke Strong Abs Work

Strong core muscles are essential for any type of weightlifting. They pull the belly in a raise intra abdominal pressure, with the same action rounding the lower back. The stronger the abs, the stronger the lift.  But it's really hard to pull your belly in effectively with an arched back... Just try it!).  

Strong abdominals prevent shear of the segments, especially important when bending & lifting (bottom left image).

The widespread use of kidney belts in Olympic weightlifting illustrates the importance of a strong core. You will read in the page Best Exercises for The Lower Abs that strengthening the lower abdominal muscles is more preferable than going for six-pack strengthening (that largely targets the inefficient rectus abdominis). Stronger abdominals also make sure you don't have a mishap at the other end of the spectrum when doing any small incidental movement, such as picking up a coffee!

Strong abdominals make the pressurised intra-abdominal space work like an airbag to support the spine at the front (right image).

Efficient Lower Abdominal Muscles Perform Several Functions

• Higher intra-abdominal pressure reduces forward shear of lumbar segments
  
  
• Higher intra-abdominal pressure offloads excessive disc compression
  
  
• High intra-abdominal pressure helps the spine straighten under load
  
  
• Pulling the belly in rounds the lower back and pre-tensions the spinal ligaments
  
  
• Rounding the lower back reduces loading on the delicate lumbar facet joints
  
  
• Recruiting lower abs helps recruit the pelvic floor
  
  
• Stronger abdominal contraction reduces over-activity from erector spinae

Are Deadlifts Bad for You? No, Not if You Avoid Over-Domination of the Long Spinal Muscles by Arching the Back

A strong abdominal contraction raises intra-abdominal pressure and 'lengthens' the spine, invoking greater tension of the spinal links 

An important truism of muscle function is that over-activity of 'agonists' causes reflex under-activity of 'antagonists'. In this instance, overuse of the back extensors to arch the low back makes it difficult to switch on the abdominals. With a massive contraction of gluts and erector spinae it's almost impossible to pull the belly in. Read more about  best lower abs exercises and worst abs exercises. 

Are Deadlifts Bad for You? No, Not if You Invoke the Deep Spinal Muscles 'Multifidus'

The deep spinal muscle 'multifidus' straightens each individual spinal segment.  Working eccentrically ('paying out') it controls the spine going forward into a spinal bend. 

Multifidus is the all-important spine straightening muscle. If you try to straighten your back without it (let alone lift 2 or 3 times body weight) you make things difficult and rely too much on the gluts and the already-dominant erector spinae, the long cable muscles.  Erectore spinae must work frenetically hard... and it's too easy to strain the back this way. 

Deadlifts tend to reinforce a faulty pattern when they use a bowstring action of the back and fail to 'unfold' or unfurl from a slightly bent posture to straight. This makes a hard job harder. With a low-back-arched-action hingeing at the hips you are literally lifting without the benefit of multifidus, the deep spinal muscle that unfurls the spine cog by cog. Thus, you are lifting with one powerful group missing in action - and making the effort so much greater. 

Deadlifting with an over-arched lower back causes a dangerous downward spiral into spinal instability. With the reflex switching-off of both abdominal and deep spinal muscles an ever-increasing contraction of the long spinal muscles is invoked to hold the segments secure. This induces massive spinal compression which cannot be ameliorated by an adequate abdominal contraction to off load the vertebrae. The 'over strong' effect on the spine intensifies the cycle of breakdown, particularly at a level which has been previously hurt by a shearing strain.  

The Roman Chair exercises are usually done wrongly in the gyms (worse with a sandbag behind the neck). They are done like this as 'hyper-extension' exercises rather than 'unfurling' from the base of the spine up, head coming up last. 

The ultimate spinal strengthening to re-educate proper lifting biomechanics is the Grade 5 spinal intrinsics using the Roman Chair. However, there's a right way and a wrong way to do this exercise. For this reason it's a good idea to watch Sarah's video specifically focused on lower back strengthening. You can read more about this important video here.