Back Anatomy

Superficial Muscles

• Trapezius
• Attaches from C7-T12 spinous processes
• Inserts on the spine of scapula and the lateral third of the clavicle
• Rhomboid Minor
• Superior to rhomboid major
• Attaches from C7-T1 spinous processes
• Inserts on the medial border of the scapula
• Rhomboid Major
• Attaches from T2-5 spinous processes
• Inserts on the medial border of the scapula
• Latissimus Dorsi
• Attaches from T7-L5 spinous processes, sacrum, iliac crest and ribs X-XII
• Inserts on the humerus
• Levator Scapulae
• Attaches from C1-4 transverse processes
• Inserts on the medial superior portion of the scapula

Intermediate Muscles

• Serratus Posterior Superior
• Attaches from C7-T3 spinous processes
• Inserts to upper border of ribs II-V
• Serratus Posterior Inferior
• Attaches from T11-L3 spinous processes
• Inserts to lower border of ribs IX-XII

Deep Muscles

• Suboccipital muscles
• Splenius
• Capitis and cervicis
• Erector Spinae
• Longissimus
• Capitis, cervicis and thoracis
• Iliocostalis
• Cervicis, thoracis and lumborum
• Spinalis
• Capitis, cervicis and thoracis

Superficial and intermediate muscles are innervated by anterior rami of spinal nerves (or cranial nerve XI for the trapezius). Deep muscles are innervated by the posterior rami of spinal nerves.

Transversospinales Muscles

Three groups of muscles that connect the transverse processes to the spinous processes superiorly, sitting underneath the erector spinae. When they contract bilaterally they work similarly to the erector spinae, but when they contract unilaterally they rotate the spine.

• Semispinalis
• Most superficial. Cervical and thoracic spine. Attaches over 4-6 vertebrae.
• Multifidus
• Intermediate. Full length of spine. Attaches over 2-4 vertebrae.
• Rotatores
• Most deep. Full length of spine. Long rotators attach over 2 vertebrae. Short rotators attach over adjacent vertebrae.

FAQ - What is a Muscle Knot?

This is undoubtedly one of the most commonly questions asked during a massage, alongside with 'What does a muscle knot feel like?' and 'What does massage actually do?' These questions are not always easy to answer, and with many possible answers being thrown around the internet finding an easy way to explain what a 'knot' is and how your massage techniques are beneficial is difficult.

Up until this point I have done my best to keep it simple, primarily to not feel like I'm throwing medical terms at holiday makers who were ultimately looking to relax. From my experience they are commonly used areas that are used statically or in a small range, resulting in the individual fibres becoming almost 'sticky' and struggling to glide over one another in full range. This links in well with the term 'adhesion' that is frequently used interchangeably with 'knot', as the effect a small drop of adhesive would have provides good imagery. Using whichever term you prefer, they are typically common in the levator scapulae, trapezius, rhomboid and quadratus lumborum muscles from desk work (or other jobs that often use similar posture, including drivers, waitresses and massage therapists themselves). 

Generally I find that it is not only one point in the muscle that is 'knotted', with increased tension along the length of the muscle presenting in almost all cases. Additionally where muscles overlap, adhesions can start to form not only between the individual muscle fibres, but the fascia surrounding whole muscles. As a number of muscles work in different directions to perform a single movement, you can almost think of it as increased friction between the muscles leading to increased difficulty and discomfort.

Many sources refer to 'knots' as 'myofascial trigger points' that occur in typical patterns in individual muscles. There is variable methodology and theories that practitioners use to diagnose, with a number of classifications (e.g. active, potential, latent or key). Trigger point maps indicate roughly 620 possible trigger points across the body, which on observation support areas that I work through on a daily basis. These areas are frequently described as predisposed to trigger points, which I think works well with the typical pattern most desk workers seem to follow. Other than postural or ergonomic causes; trauma, overuse, strain, imbalanced mechanics, poor nutrition, stress and cold temperatures can also exacerbate trigger points. 

Knots, trigger points, adhesions or whatever else you may refer to them as are also commonly described as small areas of tension, whereby the muscle has been used and ineffectively relaxed afterwards. I see this commonly amongst skiiers, as it is one of the rare forms of exercise where few warm up or stretch and most cool downs are very much sedentary with an apres-ski pint. There are definite ways to avoid or lessen the effect of knots and prevent damage:

Number 1) Have a long 'warm up' run as your first run of the day. A nice meandering blue at a relaxed pace is perfect. An actual warm up or stretch is often ineffective due to the time taken to then begin skiing and the limitations presented by your equipment.

Number 2) Use heat to help vasodilate your blood vessels; increasing blood flow to the area and promoting recovery. Hot tubs and baths work well for this, relaxing you both physically and mentally. However be cautious that with an injury you want to reduce blood flow to the area for the first 48 hours, meaning that the hot tub won't do you any good. If you are in doubt contact a healthcare professional.

Number 3) Take the time to stretch. Yes, I know it's a faff, but the benefits are beautiful. The quadriceps, gluteals and calves commonly tighten up in skiiers and are possible to slip into your daily routine. For example, stretch your quadriceps whilst waiting for the kettle to boil, your gluteals just before you go to sleep or you calves when you're brushing your teeth. The longer you hold the stretch, the more time you are giving your muscles to stretch along all the areas of tension, rather than just the one it reaches first. So try to hold the stretch for a minimum of 15-30 seconds.

If it's too late and the above aren't helping to lessen the effect; see a trained therapist. This can be a remedial or sports massage therapist, acupuncturist or whoever else works for you. Although they can be expensive, the benefits are often quick and effective. However if you are commonly obtaining areas of tension or knots it's almost certainly worthwhile booking in with a physiotherapist (or osteopath or chiropractor if you prefer) to try and identify the cause and work on techniques you can use to prevent them, rather than managing the symptoms when they appear.

Fractures

A fracture presents as a  loss of continuity in the substance of the bone. It can present as open, closed or complicated. Causes include direct violence (e.g. trauma), indirect violence (e.g. twisting), fatigue and stress (e.g. osteoporosis). 

Fracture Healing Process

• Haematoma Formation
• Within 3 days
• Adjacent vessels are torn, limited blood supply to osteocytes
• Sub-periosteal and endosteal cellular proliferation
• Haematoma reduces
• Cellular tissues push in
• Callus Formation
• Proliferated cells lay down intercellular substance (chondrogenic and osteogenic)
• Becomes calcified to form woven bone/callus
• Bone is united
• Consolidation
• Woven bone transformed into lamellar bone
• Osteoclasts burrow through the debris
• Osteoblasts fills in gaps between fragments (takes months)
• Should be weight bearing by this stage
• Remodelling
• Bone strengthened in lines of stress by continual formation
• Restored to original form

Fracture Healing Time

Knee Differential Diagnosis

The Mechanism of Injury (MOI) is useful subjective information that can be used to direct the objective assessment. This includes discussing the location of contact, location of pain, history of previous injury, areas of anaesthesia/dysaesthesia or weakness and swelling. 

Anterior Cruciate Ligament (ACL)

• Non-contact twisting injury in flexion
• Blow to the hyperextended knee
• In young patients, ACL tear is the most common cause of acute swelling
• Tests include Lachman's, Anterior Drawer and Pivot Shift
• Imaging includes a standing AP x-ray

Posterior Cruciate Ligament (PCL)

• Blow to the flexed knee (e.g. dashboard injury)
• Posterior knee pain
• Tests include Posterior Drawer, Posterior Sag Sign and Quadriceps Active test

Medial Collateral Ligament (MCL)

• Blow to lateral aspect of the knee (valgus injury)
• Acute medial pain
• Tests include valgus laxity at 0 to 30 degrees of knee flexion

Posterolateral Corner (PLC)

• Blow to the hyperextended knee
• Blow to the medial aspect of the knee
• Acute lateral pain, including Lateral Collateral Ligament (LCL)
• Tests include varus opening at 30 degrees of flexion, posterolateral drawer test, reverse pivot shift test and the figure-4 test.
• Varus thrust gait

Meniscus

• Non-contact twisting injury in flexion
• Acute pain (med/lat)
• Chronic pain (med/lat) indicates a degenerative meniscal tear
• Acute swelling
• Lack of full extension (bucket handle tear)
• Lack of full flexion may be indicative of an injuy to the posterior horn of the mensci
• Posterior knee pain on flexion

Patellofemoral

• Anterior knee pain with flexion of the knee
• Patella translation
• Retropatellar Crepitation (indicative of chondromalacia)
• Imaging includes a patellar sunrise x-ray
• Weakness in quadriceps strength

Patella Subluxation or Dislocation

• Non-contact twisting in extension
• Increased risk with patella alta (when the patella is higher than normal, therefore disturbing the interactions with the trochlear groove)
• Acute anterior pain
• Acute swelling
• Deformities (typically lateral)

Infections and Tumours

• Chronic swelling (also indicative in osteoarthritis)
• Joint warmth or redness may be indicative of infection (aspiration may be required to evaluate the synovial fluid)
• Bloody effusions are more consistent with trauma or tumour
• Non-bloody effusions are more consistent with infection or inflammatory arthritis
• A Baker's Cyst normally indicates that swelling elsewhere in the joint has leaked posteriorly between the semimembranous tendon and the medial head of the gastrocnemius tendon
• Knee effusion may limit full flexion
• Imaging includes CT and bone scans for tumours or another bony pathology
• Aspiration invasive testing may also be carried out with acute effusion

Chronic Pain

• Chronic medial pain indicates a degenerative meniscal tear, medial compartment arthritis or pes anserine bursistis
• Chronic lateral pain indicates a degenerative meniscal tear, lateral compartment arthritis or biceps bursitis
• Chronic anterior pain indicates patellofemoral joint chondromalacia and patellar tendonitisa
• Chronic posteroir pain indicates posterior horn meniscal tears or a Baker's (popliteal) cyst

History of Previous Injury

Patients who have had previous ligament injuries are at an increased risk of secondary injuries. Additionally, patients who have had menisci resections are at a high risk of developing arthritis, which could present with pain and swelling upon activity.

Anaestheia or Dysaesthesia or Weakness

Direct blows to the anterior aspect of the knee can cause sensory changes in the infrapatellar branch of the sapenous nerve, resulting in altered sensation on the anterolateral aspect of the knee.

Blows to the anteromedial knee or a varus of hyperextension injury can stretch the common peroneal nerve, resulting in reduced sensation in the first dorsal web space and lateral foot. There may also be motor weakness in the extensor hallucis longus, extensor digitorum longus, peroneals and tibialis anterior.

Medial knee injuries may have decreases sensation along the medial aspect of the leg due to the saphenous nerve.

It is important to assess the function of tibial nerve for severe injuries by assessing sensation on the sole of the foot as well as plantar flexion and inversion strength. 

Posterolateral Corner

The posterolateral corner (PLC) is a collective term for multiple structures within the knee joint. These include:

• Tibia
• Fibula
• Lateral Femur
• IT band
• Long and short heads of biceps femoris tendon
• LCL (otherwise known as the fibular collateral ligament)
• Popliteus tendon
• Popliteofibular ligament (PFL)
• Lateral gastrocnemius tendon

The three most important static stabilisers are the LCL, popliteus tendon and PFL as they restrict varus, external rotation and posterior translation.

From 0 to 30 degrees of flexion, the LCL is the main structure preventing varus opening of the knee (although the IT band assists). The popliteofibular ligament connects the popliteus muscle at the musculotendious junction to the posterior, medial portion of the fibular styloid and stablises the knee during external rotation.The popliteus tendon provides static and dynamic stabilisation to the knee during posterolateral rotation.

The two convex opposing surfaces (lateral femoral condyle and lateral tibial plateau) makes the posterolateral corner more unstable than the medial aspect, therefore increasing the risk of poor healing post-injury.

Specialised Tests

Varus Stress Test at 0 and 30 degrees

       Grade I - Pain but no gapping of the lateral joint space

       Grade II - Some gapping of the lateral joint space, but with a definite end point

       Grade III - Significant gapping with no definite end point.

Increased gapping at 0 degrees typically indicates a serious posterolateral injury with a high probability of cruciate ligament involvement. Lower grades at 30 degrees are more indicative of partial LCL tears, with higher grades indicating complete tears of the LCL.

Posterolateral Drawer Test - Similar to the posterior drawer test, however the foot is externally rotated to 15 degrees. While stabilising the foot, appy a posterolateral rotation to the tibia. Increased mobility indicates injury to the popliteus complex.

Figure 4 Test - Patient lies supine and flexes the knee to 90 degrees with the ankle resting on the other knee by placing the hip into external rotation. Application of a varus stress on the knee places tension particularly on the popliteus complex. When injured, there is no tension to stabilise the lateral meniscus allowing it to medially displace into the joint, reproducing the patient's symptoms at the lateral joint line.