Degenerative joint disease of the first metatarsal phalangeal joint marked by joint fibrosis, calcification and reduced range of motion. Early detection and treatment is critical in preventing further degenerative deformities such as Hallux Valgus.
Given the importance of the first metatarsal phalangeal joint to foot biomechanics, surrounding joints will respond with hypermobility and a cascade of biomechanical abnormalities.
Propulsion at toe-off gait phase will be minimised based on pain levels and bone spur restrictions.
The first metatarsal phalangeal joint complex is built to sustain approximately 60% of the bodyweight load during gait and stance.
Any biomechanical faults that increase the weightbearing load on the hallux joint will start to damage the joint capsule causing inflammation and reduced motion, commonly referred to as Hallux Limitus.
Chronic stress to the first metatarsal phalangeal joint will further destruct the joint capsule, affecting articular cartilage and allowing for the development of bone spurs. This advanced stage of rigidity is termed as Hallux Rigidus.
The most common biomechanical cause of this aberrant weight distribution is a hyperpronated foot, often coupled with a toe-out gait posture and tight calf musculature.
The goal of MASS4D® in Hallux Rigidus is to offload the excess weight from the first metatarsal phalangeal joint. A healthy gait is characterised by medial forefoot load, and it is essential that this load must be reduced to 60% to allow for healing.
Early stage intervention will certainly include palliative modalities; however, a functional biomechanical approach is the most effective conservative plan.
It should be noted that MASS4D® is one component of a complete active rehabilitation program for Hallux Rigidus, which also includes lower-limb stretching and strengthening.
MASS4D® orthotics aim to support the foot in its corrected foot posture with maximum healthy supination during closed-chain posture in stance phase. That support will remain with the foot throughout all phases of gait due to its full contact construction.This level of customisation achieved through Gait-Referenced Casting and Calibration will ensure the foot is allowed functional pronation and supination whilst restricting the foot from the pathological ranges of motions that caused the onset of Hallux Rigidus.