From the Guidelines
A foot doctor diagnoses a hypermobile first ray through a combination of physical examination and weight-bearing radiographs, as they are the most useful initial imaging study to evaluate the position of the first metatarsal relative to other foot bones. The diagnosis of a hypermobile first ray is primarily clinical, relying on physical examination techniques such as the Klaue test or the sagittal plane stress test, where the podiatrist stabilizes the foot while manipulating the first metatarsal to assess excessive movement 1. These manual tests are crucial in assessing the degree of mobility of the first ray.
The use of imaging studies, particularly weight-bearing radiographs, is essential in confirming the diagnosis, as they provide valuable information on the position and alignment of the first metatarsal bone in relation to the other bones in the foot 1. While advanced imaging modalities like MRI or CT scans may be used to assess soft tissue damage or subtle bone abnormalities, they are not typically the first line of imaging in the evaluation of chronic foot pain, including hypermobile first ray 1.
Key points to consider in the diagnosis of a hypermobile first ray include:
- Physical examination techniques to assess excessive movement of the first metatarsal
- Weight-bearing radiographs to evaluate the position of the first metatarsal relative to other foot bones
- The importance of accurate diagnosis to prevent complications such as bunions, metatarsalgia, and arch pain
- The use of advanced imaging modalities like MRI or CT scans to assess soft tissue damage or subtle bone abnormalities, if necessary.
From the Research
Diagnosis of Hyper-Mobile First Ray
To diagnose a hyper-mobile first ray, a foot doctor may use the following methods:
- Clinically, hypermobility is evaluated by determining sagittal motion (the grasping test) and transverse motion (the clinical squeeze test) 2
- Identifying signs such as the presence of a dorsal bunion, intractable plantar keratosis beneath the second metatarsal head, and arthritis of the first and second metatarsocuneiform joint 2
- Radiographically, hypermobility is evaluated by measurements from the modified Coleman block test (for sagittal motion) and the radiographic squeeze test (for transverse motion) 2
- An operational definition of first ray hypermobility has been proposed, which includes dorsal displacement that measures greater than 8 mm, accompanied with signs and symptoms consistent with loading insufficiency of the first ray 3
Evaluation Methods
The evaluation methods for hypermobility of the first ray include:
- Measurement of first ray elevation and translation using a simple device 4
- Finite element analysis to investigate the joint force during walking 5
- Systematic review and meta-analysis to evaluate the difference in the first ray range of motion between patients with or without hallux valgus deformity 6
Key Findings
Key findings from the studies include:
- Hypermobility of the first ray is a predisposing factor for hallux valgus deformity, especially in conjunction with extrinsic factors 2
- Increased first ray mobility is associated with several foot disorders, including hallux valgus and metatarsalgia 4
- The load transfer mechanism of the first ray is important to understand the development and pathomechanism of hallux valgus 5
- Statistically significantly increased first ray motion is found in patients with hallux valgus deformity compared with those without hallux valgus deformity 6