How do muscles get injured?

There are many ways a muscle can be injured, whether you are playing sports, decorating or towelling down after a shower. This could be through fatigue, poor warm up, poor flexibility (overstretching) and interrupted muscle contractions to name a few. Muscles can be injured by direct trauma (Impact) or indirect trauma (overloading)

Direct trauma - normally a blow/contusion/kick to the leg.

Indirect trauma – overloading.

An example of overloading a muscle could be, if you placed an empty box on the floor and return to pick it up only to discover at the point of no return that someone has filled it with lead weights, you then feel the hairs on the back of the neck stand up as you realise therefore straining the associated muscles and now waiting for the pain and tightness to begin.

This injury has occurred because the brain has remembered the box was empty, and the weight of it, but didn’t know something had changed (the lead weights) therefore the brain and central nervous system had not recruited enough muscle fibres to lift the box which resulted in overloading and injuring the ones that were recruited.


An example of an interrupted muscle contraction…

Imagine you are having a kick about with the kids, you run up to the ball, wind up to score that goal and impress your 5 year old when suddenly your mate sticks his hoof right in the way without you seeing it and bang, you make contact with something else other than the ball, searing pain goes through the thigh and you are no longer impressing your 5 year old as you end up crying and hopping on one leg.

This injury to the thigh has happened because there was an interruption in achieving a task, such as kicking the ball, the brain had again worked out, distance from the goal, how much power, speed, timing and muscle recruitment needed, all this power was stopped abruptly without the brain having time to react and caused excessive contraction causing injury to the muscle or soft tissue.


As we said muscles can be injured as a result of direct/indirect trauma, these can also be divided into Tears (strains) and hematomas (bruises)


Grades of injury (Muscle Strain/Tear):

Grade 1

  • Mild damage to muscle fibres
  • Mild bleeding within the tissue  (possible bruise, see hematomas)
  • Pain
  • Slight loss of strength
  • Slight loss of motion
  • 2-3 weeks healing

Grade 2

  • Moderate to a large amount of muscle fibres torn
  • More pain than grade 1
  • Significant loss of strength and motion
  • Extensive Bruising will appear later, unless contained within the muscular sheath.
  • Possible visual and palpable deformity such as a dip or lump in the tissue
  • 3-8 weeks healing

Grade 3

  • complete rupture or only a few fibres remaining
  • Pain
  • Extensive bruising will appear quickly
  • visual and palpable deformity such as a dip or lump in the tissue
  • Medical attention required, possible surgery to reattach.
  • 8 + weeks healing, depending on severity and surgery


A few points to remember…

  1. Most injuries are Grade 1 and can heal quickly with correct treatment and advice.
  2. The healing times depends on the severity of the grade, the person, their age and their patience and are not set in stone.
  3. The healing time for the injury is not the same as being functionally fit, this will take several week longer.
  4. Just because the injury has healed it does not mean you are 100% fit, therefore you cannot begin where you left off.
  5. Active rest, so you have an injury, it doesn't mean you have to stop everything! for example, a sprained wrist will not stop you from training legs.
  6. Reduce calorie intake, you do not want to put on weight during injury, as your recovery will be slower.


Ligament sprains

Ligament injuries have grades 1, 2 & 3 similar to muscle strains, see above, but can take a significant amount of time to heal due to the lack of blood supply to the tissue, whereas muscles have a rich blood supply and will heal far quicker.


Hematomas (bruises)

This could be brushed off as ‘just a bruise’ but it is still trauma to the muscle or surrounding tissue and worth getting checked out! Incorrect management could have a detrimental effect.

Bruises have 2 categories...

Inter-muscular hematoma, this is where there is bleeding between muscles as a result of damaged blood vessels, muscle and fascia.  There will be a pressure build up and swelling within and around the site of injury but this will subside quickly as the bleeding is not contained within a space and is absorbed quickly.  A bruise will present itself within 24-48 hrs after, and may appear distal to the actual site of the injury due to gravity.  Muscle function should return quickly and have a complete recovery.

Intra-muscular hematoma, this is the more troublesome one, here the bleeding cannot escape the muscle fascia (sheath) and gets absorbed very slowly, pressure remains within the muscle sheath and there will be an acute temporary compartment syndrome which can last beyond 72hrs, swelling is persistent along with impaired muscular function.



Phases of injury

Acute – From the moment of injury 1st aid and advice needed. You will be experiencing a substantial amount of pain. Follow the P.R.I.C.E principle as follows...

Protect – immobilise, bandage, strapping, taping, crutches, padding, sling etc.

Rest – do not do anything for 48- 72 hrs.

Ice – or cool pack, to control the amount of bleeding and swelling, not to be applied over an open wound, eyes or genitalia.

Compression – inflatable cuff, bandaging, to help reduce the amount of swelling.

Elevation – keeping the injury above the heart (if possible) to reduce pooling of fluids.


Sub-acute – repair phase

From approx. days 3, 4 or 5

Treatment and advice required. Pain will still be prevalent.

This is where the tissues will begin to reattach and begin to repair in the form of scar tissue (collagen), bleeding should have stopped.  The tissues are very weak during this phase and will still need protecting.

From day 5 mild stretching may be introduced, but cautiously as over stretching could re-injure the site.

From day 6 (depending on severity) heat may be introduced in the form of contrast bathing.


Intermediate phase – remodelling and rehabilitation 14– 21 days from day of injury

Scar tissue is now really doing its thing, but can get carried away.  This phase is important to have soft tissue treatments to manage how the scar tissue is performing so that the injury heals faster and causes less problems in the future.

Light Strength/resistance work may be introduced along with more intense stretching, again be careful when performing stretches.

The site of injury is still vulnerable and care should be taken during rehab, the key word is ‘progressive’.


Functional rehab phase  day 21 onwards

This phase will mean scar tissue has stopped forming and you have done everything right and are on the way to return to your past time, sport or work. Care should still be taken as you are still not fully fit and re-injury would be devastating at this point.


Please note that the content in the above phases are fairly brief and will go into more detail with the individual at the time of treatment, the time frames are approximate depending on type of injury and the severity.


Why do muscles spasm and cause pain?

All muscles and tendons have receptors which tell us the degree of stretch or contraction going on.

The stretch reflex uses mainly the muscle spindle receptors, these monitor the length of the muscle, so if you are stretching too far too quickly the stretch reflex will kick in to protect the joint or muscle. (When you have a health professional hit your knee with a small hammer, this is what they are testing).

The Golgi Tendon Organ (GTO) receptors, are mainly found where the muscle merges with the tendon.  These receptors detect the amount of tension and are thought to inhibit a muscle if the load is too great or even excite the muscle in which they are situated to prevent injury to the tendon or joint.

The reflexes are very complex and they still don’t know precisely the role of the GTO.

So you have over stretched (maybe a slight injury has occurred) and the muscle has gone into a protective stretch reflex and for some neurological reason has not let go, this muscle is now tight and reacting with the nerves that pass through the tissue causing pain! It’s now my job to release this spasm so things can return to normal.


Tight muscles are 'Knot' what we want...

Knots in the muscle could also be active trigger points, knots may result from the stretch reflex, fatigued muscles, and poor posture resulting in shortened muscle groups, symptoms could be radiating pain, referred pain such as sciatic symptoms, a deep aching pain, numbing, tingling, headaches and even toothache.

Drs Janet Travell & David Simons describe a trigger point as "A highly irritable localised spot of exquisite tenderness in a nodule in a palpable taut band of skeletal muscle’ and these can certainly be a PAIN and cause DISCOMFORT" .  However, once the trigger points have been identified, they can easily be treated.

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