Pre-Reading & Videos for Forefoot Masterclass

Click on any coloured writing = a link to read or video to view.
Click on pictures to enlarge them.

Abbreviations
MT        Metatarsal
STJ       Subtalar Joint
TMTJ    Tarsometatarsal Joint
MTPJ    Metatarsophalangeal Joint
PIPJ      Proximal Interphalangeal Joint    
DIPJ      Distal Interphalangeal Joint   

AbH       Abductor Hallucis
FHL       Flexor Hallucis Longus
FDB       FH Brevis
FDL       Flexor Digitorum Longus
FDB       FD Brevis

Terminology / Definitions / Biomechanics

The key movement of the ankle joint complex are
  • Plantaflexion and dorsiflexion, occurring in the sagittal plane
  • Abducation and adduction, occurring in the transverse plane and
  • Inversion-eversion, occurring in the frontal plane
Combinations of these motions across both the subtalar and tibiotalar joints create three-dimensional motions called supination and pronation. Both terms define the position of the plantar surface of the foot (sole). During supination, a combination of plantarflexion, inversion and adduction causes the sole to face medially. In pronation, dorsiflexion, eversion and abduction act to position the sole facing laterallywww.sciencedirect.com

Supination is a combined movement consisting of:
- adduction of the hindfoot
- inversion of the forefoot
- plantarflexion

Pronation 
- abduction
- eversion
- dorsiflexion


There are two axes of the forefoot, across the metatarsal heads:
- transverse axis across MT heads 1 & 2  (high gear propulsion)
- the oblique axis across MT heads 2 - 5  (low gear propulsion)


Arch Apex (Apex of the foot) is the highest point of the medial longitudinal arch. The navicular should be the bone at the apex of the foot.


Foot deformities:
When observing a foot you can describe the medial longitudinal arch as being reduced or increased, but when there is a large deformity we use:
Pes planus = very flat foot
Pes cavus = very high arched foot

Lesser toe deformities:
Mallet toe


Functional Anatomy
  • The 1st toe (the hallux) has 2 phalanges
  • Toes 2-4 have 3 phalanges
  • The 5th digit has 2 Phalanges
  • The shape of the bone surfaces of the MTPJs are not inherently stable
  • The IPJ are hinge joints, stabilised by the collateral ligaments and plantar capsular thickenings.
    • The collateral ligaments provide varus/valgus stability
    • The plantar plate and plantar fascia resist upwards displacements

Soft tissues of interest
  • Extensor expansion
    • is where the FDL originates from distally
    • and where the lumbricals insert

Ligaments
Calcaneal ligaments
Navicular ligaments

Phalangeal ligaments



Muscles & their tendons

  • Muscles are either Extrinsic (originating from lower leg) or Intrinsic  (originating from within the foot) & muscle imbalance can lead to toe deformity.
  • There are 4 layers of muscles in the foot:

Now read more about each muscle and it's function by following the links. The asterisked muscles are the most important for you to pre-read.

Hallux
*FHB (and function)
*EHB (and function)

Lesser MTs
EDB


https://i0.wp.com/boneandspine.com/wp-content/uploads/2015/10/metarsal-bones-attachments-plantar.png?ssl=1Attachments on foot - dorsal surface


  • Interossei

  • Lumbricals

Bones
***Sesamoids (and review their function)
Including the crista (a bony ridge on the plantar aspect of the 1st MT head). Skip to 0:53 seconds in this video.


Neurological
When you see a pes cavus foot or clawed toes ensure to rule out an underlying neurological causes, neuromuscular disorders (NMD's) and motorneurone disorders (MND's).
These will present as bilateral foot shape changes.

For example (this list is not exhaustive):
  • Progressive muscular atrophy
  • Amyotrophic Lateral Sclerosis
  • muscular dystrophy
  • spinal muscular atrophy
  • hereditary neuropathy
    • Charcot-Marie-Tooth disease
  • congenital myopathy
  • Friedreich's ataxia
  • myasthenias
  • myotonic syndromes
  • metabolic myopathies
  • inflammatory myopathy
  • Poliomyelitis
  • MS
  • Stroke 
  • Spinal tumour
  • Brain tumour
  • CP
  • Peroneal muscle atrophy
  • Myelopathy
  • Myelomeningocele

BEWARE OF A UNILATERAL PES CAVUS FOOT CHANGE - THIS IS A RED FLAG AND A SPINAL TUMOUR WILL NEED TO BE RULED OUT

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