Study: When is bending too much?

Alessa 2017

How long is too long, to be in a forward, bent posture? Many of us spend hours doing house chores; weeding, DIY, working on the car etc. Not to mention the time spent leaning over a computer desk or looking down at your phone.

Back pain

Your muscles play an amazing role of suspending us in these positions, but just like with exercise our muscles will reach a point of fatigue. When the postural muscles aren’t able to provide the support we then rely on “passive” structures like ligaments and fascia, which is not their primary role, eventually leading stress and increased risk of injury.

This study looked at 2 angles of the spine leaning forwards and found that within 40 seconds the participants transitioned from the support of postural muscles to the passive structures. While this was found to be a natural transition the prolonged strain on the passive structures has been shown to increase the risk of lower back pain as suggested in another study.

As mentioned in a previous blog, these positions are not “wrong” but it’s better for the overall health of the spine to regularly change position and break from sustained load on an individual structure to provide balance.

Abstract

Static trunk bending is an occupational risk factor for lower back pain (LBP). When assessing relative short duration trunk bending tasks, existing studies mostly assumed unchanged spine biomechanical responses during task performance. The purpose of the current study was to assess the biomechanical changes of lumbar spine during the performance of relatively short duration, sustained trunk bending tasks. Fifteen participants performed 40-s static trunk bending tasks in two different trunk angles (30° or 60°) with two different hand load levels (0 or 6.8 kg). Results of the current study revealed significantly increased lumbar flexion and lumbar passive moment during the 40 s of trunk bending. Significantly reduced lumbar and abdominal muscle activities were also observed in most conditions. These findings suggest that, during the performance of short duration, static trunk bending tasks, a shift of loading from lumbar active tissues to passive tissues occurs naturally. This mechanism is beneficial in reducing the accumulation of lumbar muscle fatigue; however, lumbar passive tissue creep could be introduced due to prolonged or repetitive exposure.

 

Alessaa F. et al (2017) Changes of lumbar posture and tissue loading during static trunk bending. Human Movement Science

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Understanding your Nervous System

You can’t control the wind, but you can adjust your sails

Our nervous system has a connection to all structures in the body. Without a healthy working nervous system most bodily functions suffer, our performance in life situations and sport are hindered and recovery from injury is impacted.

The Nervous system

Part of our central nervous system, within our subconscious is a mechanism for handling stressful situations. This is called the Autonomic Nervous system. It branches into two parts; the Sympathetic NS (SNS) and Parasympathetic NS (PNS). The SNS stimulates the bodily functions preparing us for the “fight, flight or freeze” in life threatening situations. The PNS is the other branch that prepares us for “rest, digest and heal”. It’s the PNS that should be the primary driver of our physiology.

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Using the mailman and dog as an example. Most canines are territorial and when unknown visitors arrive they become defensive, will bark and jump at the door. It’s ready to fight. When the postman leaves, the dog quickly forgets what happened and is able to fall asleep within minutes. It recognises the threat has gone and can immediately relax.

Consider yourself in the same situation, feeling threatened of an intruder. You might shout at them to leave or prepare to engage with them. When the person retreats could you relax straight away or will you be on edge for hours or even days?

The SNS is important but only has a purpose for the short term, to allow us to deal with threatening situations. Unfortunately with hectic lives, our brain interprets these physical and mental stresses as life threatening, which frequently triggers the SNS on a daily basis. Constantly stimulating SNS can lead to chronic issues…

  • Anxiety
  • Fatigue
  • Irritability
  • Sleep disorder
  • Non-working muscular tension
  • Hyperventilation
  • Adaptation failure
  • Cognitive dysfunction

The brain struggles to identify physical stress’ and imagined stress’. Anxiety of an electricity bill, job cuts at work or relationship issues will fire up the SNS.

Throughout exercise/sport our PNS and SNS working in balance. Depending on particular stressors like speed, distance, duration, the SNS may start to have a greater influence. It’s important to get into our PNS state for improved decision making, better oxygen delivery and for achieving optimal recovery.

Ways of Activating the Parasympathetic Nervous System

The PNS is the system we should be using most frequently . Therefore finding methods of staying in this state even when put under perceived levels of stress are important.

1. Breathing Mechanics

The way we breath has a deep connection to the autonomic nervous system. Shallow, apical breathing has a direct link to our SNS. But taking Deep diaphragmatic breaths stimulates the PNS. Using breathing exercises daily can help train you into a more relaxed state.  Methods such as….

Wim Hof Method

Apnea Breathing

Kapalbhati Breathing

2. Meditation Practices

Through channeling your thoughts and breathing, meditation can help induce a state of relaxation. Following this 5-10 minutes daily can help improve many different functions. Easy to use apps for this are…

Head Space

Wildflowers

                      SoundCloud – Mindfulness Works

3. Muscle relaxation

Using methods like meditation or yoga are ways of achieving muscle relaxation. Having massages and soaking in a hot bath also offers a way of relaxing muscles. The release of tight muscles indirectly sends signals to the brain to activate the PNS and switch off the SNS.

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Lunge Hip Mobility

This is the second part of the hip series. These hip shapes are positions that we should all be striving for to have confidence and feel safe to function if exposed to complex positions. 

Following on from the blog hip opener for the hinge shape is our next hip position we should try to achieve. The lunge shape is full extension and internal rotation of the hip with the knee positioned behind the hip and foot pointing forwards. This shape is most seen in lifters doing split jerks, kicking a football, ball throwing. But most commonly seeing this lack of range with runners, not utilising the full hip extension in the push off at the end of stance phase.

Over the years adaptive changes happen either through injury or more with positions we adhere to. The most common being sitting, which results in anterior structures of the hip becoming limited. Lacking the end range of this movement could mean we’re selling our self short of momentum, power or endurance.

Running-lunge

Using the picture of long distance runner Mo Farah, he demonstrates a great lunge shape at the hip. While maintaining a neutral spine he manages to reach full hip extension and toes are pointed forwards, maintaining the internal rotation of the hip. Lacking hip extension can compromise running form of the upper limb and spine. But as you can see he reaches a good press shape of the opposite shoulder in the arm swing making his running style extremely efficient and balanced.

Below are a series of stretches and mobility exercises to help improve your lunge shape.

Couch stretch

If hip flexors are tight this is one of the best stretches for improving length back. A long sustained hold of this stretch with full diaphragmatic breathing over 2 minutes is extremely effective.

COUCH STRETCH ❌ There are few better exercises to open the hip flexors than the couch stretch. It's not everyone's favourite but it's effective. ❌Take one leg up the wall or box so your shin is resting on it and the knee is on the floor. If you don't already feel the quads stretch. Take the opposite foot through. While keeping the abdominals and gluteus tight, gently push the hip forwards. Hold this stretch for up to 2 minutes. #fundamentalPhysio #physio #physiotherapist #physiotherapy #crossfitnewmarket #crossfit #gym #fitness #squat #hiphinge #lunges #auckland #newmarketnz #mobility #mobilitywod #flexiblehips #strongerhips #injuryprevention #athelete #rehab #sprints #boxjumps #football #basketball #hipflexors #running

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Illiopsoas Trigger Point Release

This muscle sits within the abdominal cavity and if tight it will feel sore with pressure through the abdominal wall towards the muscle. At first the pain can be quite high but relaxing into the pressure overtime the pain subsides and will feel looser once released. Aim for 1-2 minutes hold.

Hip flexor stretch (with band)

Another hip flexor stretch with a joint mobilisation using a band. Position the knee behind the hip. Allow the band to pull the hip forwards, contract the glutes to get the best anterior hip stretch.

Quads and inner thigh release with LaX ball

A lacrosse ball is a great tool for isolating sections of tight muscle. Rolling on the ball like you would a foam roller will be more effective, if tolerated. Then opening up inner thigh/hip adductors using the kettle bell handle. The knee flexion/extension stretches the muscle through range while being tacked down.

Suspended split stretch

This is for the more adventurous. It will help your lunge go deeper while increase stretch through the hamstrings. Throughout this movement, it is important to keep the glutes switched on to avoid hanging of the hip capsules. Spend around a minute each direction.

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