In this series, I share one complex per post. Starting with the sagittal big toe, working my way up to the sagittal thumb, before doing the same with the complexes of the frontal (aka, coronal) and transverse (aka, horizontal) planes, respectively. The first post (read HERE) in the series explains single- and multi-complex muscles, introduces complexes as I use them in Anatomy by Planes, and explains why complexes make it easier and more effective to resolve pain complaints through treatment and exercise. Enjoy!
The Sagittal Big Toe
The sagittal big toe is the first complex of the sagittal plane. It serves as a key anchor and pivot point during functional movement. The orange colored parts of the integumentary, skeletal, and muscular systems (see below) belong to it and are involved in its flexion and extension motions.
The skin, joints, and muscles of the sagittal big toe are reciprocally related to each other (intra-complex). The complex as a whole is reciprocally related to its neighboring complexes (inter-complex). Through these relationships, the sagittal big toe can contribute to and help resolve a wide range of pain conditions, injuries, and dysfunction.
Associated Pain, Injuries, and Dysfunction
- Hallux limitus [1, 2]
- Hallux rigidus [1, 2]
- Turf toe [3, 4, 5]
- Sesamoid pathology [3, 4]
- Transfer metatarsalgia [6, 7, 8]
- Plantar plate tears (2nd MTP) [9, 10]
- Hammertoe and crossover toe [10, 11]
- Morton's neuroma [12]
- Plantar fasciitis / plantar fasciopathy [13, 14]
- Lateral ankle sprain [15, 16]
- Chronic ankle instability [15, 16]
- Limited ankle dorsiflexion (functional or structural) [17, 18]
- Posterior ankle impingement syndrome [19, 20]
- Shin splints (medial tibial stress syndrome) [21, 22]
- Flexor hallucis longus tendinopathy [20]
- Achilles tendinopathy [23]
- Runner's knee (patellofemoral pain syndrome) [24, 25, 26]
- Jumper's knee (patellar tendinopathy) [27, 28, 29, 30]
- Hip flexor strain [31, 32]
- Lower back pain [31, 32]
Treating and Exercising Complex by Complex
For each of these conditions, the sagittal big toe is either the primary site of pathology or a contributing factor through the reciprocal relationships above. If a client visits you with one of these problems, treating and exercising the skin, joints, and muscles of the sagittal big toe can help them feel better; sometimes a lot, sometimes a little.
Overview Sagittal Big Toe Complex (flexion-extension)
Skin, Joints, and Muscles of the Sagittal Big Toe
ROM (range of motion): 15-40 degrees flexion and 55-95 degrees extension.
Skin: over the single-complex muscles and dermatomes T11-S2 (paraspinal posterior torso). The range includes both somatic and ANS source segments — the two are integrated at the segmental level (see van Cranenburgh, Segmentale verschijnselen en van Zutphen, Nederlands leerboek der fysische therapie in engine zin).
Joints: first metatarsophalangeal joint (aka first MTP). The first MTP joint consists of the first metatarsal, proximal phalanx, and the joint capsules, ligaments, and plantar plate complex that hold the bones together. Additionally, some literature considers the medial and lateral sesamoids (embedded in the distal tendons of the flexor hallucis brevis) part of the MTP joint, despite a distinct anatomical and biomechanical separation.
Muscles: abductor hallucis, adductor hallucis (both heads), extensor hallucis brevis, extensor hallucis longus, flexor hallucis brevis, flexor hallucis longus.
Single-Complex Muscles vs Multi-Complex Muscles
Single-Complex Muscles: abductor hallucis, adductor hallucis (both heads), extensor hallucis brevis, flexor hallucis brevis.
Multi-Complex Muscles: extensor hallucis longus, flexor hallucis longus.
Single-Complex Flexor Muscles vs Multi-Complex Flexor Muscles
Single-Complex Flexors: abductor hallucis, adductor hallucis (both heads), flexor hallucis brevis.
Multi-Complex Flexors: flexor hallucis longus.
Single-Complex Extensor Muscles vs Multi-Complex Extensor Muscles
Single-Complex Extensors: extensor hallucis brevis.
Multi-Complex Extensors: extensor hallucis longus.
References Associated Pain, Injuries, and Dysfunction of the Sagittal Big Toe
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