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.
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 laterally. www.sciencedirect.com
Supination is a combined movement consisting of:
- adduction of the hindfoot
- inversion of the forefoot
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.
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:
- 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
- Plantar fascia (AKA aponeurosis) origin and insertions + the windlass mechanism of the foot.
- Extensor expansion
- is where the FDL originates from distally
- and where the lumbricals insert
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:
***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.
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
- myotonic syndromes
- metabolic myopathies
- inflammatory myopathy
- Spinal tumour
- Brain tumour
- Peroneal muscle atrophy
BEWARE OF A UNILATERAL PES CAVUS FOOT CHANGE - THIS IS A RED FLAG AND A SPINAL TUMOUR WILL NEED TO BE RULED OUT