Alan MacGill¹; Ben Koerber²
¹HCA Florida Northwest Hospital, Margate, FL, USA
²Icarus Medical, Charlottesville, VA, USA
Abstract
The Icarus “HERMES” adjustable dorsiflexion-assist AFO was trialed in three patients presenting with varying etiologies of ankle dorsiflexion weakness and associated gait impairment. Patients included: (1) a female in her upper 50s (59 F) with multifactorial lower extremity weakness, an autoimmune/fibromyalgia overlay, and multilevel pain; (2) a male in his mid-to-upper 60s (67 M) with post-spinal surgery drop foot; and (3) a shorter, slightly obese male (76 M) with acute-onset anterior shin pain and apparent tibialis anterior dysfunction without tendon rupture on MRI. In all three cases, the HERMES AFO resulted in rapid subjective improvement in gait, elimination of assistive device use (cane or walker), and substantial reduction in associated proximal pain (back, hip, knee, or shin). Patients reported the brace as lightweight and comfortable without tissue irritation. Follow-up duration ranged from initial first return visit (Patient 1) to approximately 6 months (Patient 2); longer-term objective outcomes and standardized outcome measures are pending. These preliminary observations suggest the HERMES AFO may offer functional and symptomatic benefit in selected patients with dorsiflexion weakness who have not responded adequately to other conservative interventions.
Introduction
Ankle-foot orthoses (AFOs) with dorsiflexion assist are commonly prescribed for foot drop and related gait abnormalities arising from neuromuscular, post-surgical, traumatic, or degenerative conditions. Traditional rigid or semi-rigid AFOs can improve clearance but often sacrifice dynamic push-off, comfort, or proximal joint loading patterns. Carbon-fiber devices with energy-return properties have gained popularity for providing dynamic assistance, though lack of ankle articulation and adjustability, poor fit with off-the-shelf AFOs, and challenges donning and doffing the AFO limit patient satisfaction.
The Icarus “HERMES” is an adjustable AFO designed to provide an adjustable dorsiflexion-assist that can be released at any time by pushing a release button. Torque can be generated again with the rotation of a ratcheting dial that will produce up to 15 N-m of torque. The AFO is typically custom-made from a 3D-scan from an iPhone, and the footplate, spherical ankle joint, and calf shank conform to the patient’s ankle (it is noted that the manufacturer also produces off-the-shelf AFOs, however only custom AFOs were studied). The AFO mounts posteriorly and is of lightweight nylon construction that is 3D-printed. Unlike some anterior tibial shell designs that create suspension through wedging or limited contact, the HERMES focuses on functional dorsiflexion support without aggressive ankle hugging.
This case series describes early clinical experience with the HERMES AFO in three patients managed by a single foot and ankle surgeon. All patients had failed to achieve adequate relief with prior conservative measures or presented with gait and pain issues severe enough to warrant assistive devices.
Methods
This is a retrospective case series based on clinical recall and follow-up visits (no prospective protocol). Patients were selected based on clinical presentation of dorsiflexion weakness ± gait abnormality and were prescribed the HERMES AFO after discussion of alternatives. Fabrication was performed through standard orthotic channels.Patient follow-up occurred at the first post-delivery visit (typically scheduled after brace receipt) and, in some cases, additional visits. Outcomes were assessed subjectively via patient report and clinician observation of gait and assistive device use.
Analysis / Case Descriptions
Patient 1
- Demographics: Female, upper 50s
- Relevant history: Multiple orthopedic issues, Lupus, Raynaud’s, Fibromyalgia, Arthritis
- Primary complaints: Pain throughout lower extremity into foot, muscle weakness
- Key exam findings: Distinct weakness in ankle dorsiflexion (tibialis anterior) and digital extensors; plantarflexion strength relatively preserved
- Workup: EMG/NCS ordered to evaluate etiology (lumbar vs. peripheral vs. myopathic)
- Pre-brace status: Intermittent use of walker or cane
- Post-HERMES outcome:
- First follow-up visit (immediately after brace delivery): Reported significantly improved walking without any assistive device
- Marked reduction in multilevel pain (lower back, hip, knee) attributed to improved gait mechanics and reduced compensatory patterns
- Patient described the change as “raving” positive
Patient 2
- Demographics: Tall male, mid-to-upper 60s, non-obese
- Relevant history: Prior spine surgery (L5/S1 fusion in March 2025) with subsequent drop foot (likely iatrogenic or residual radiculopathy)
- Primary complaints: Steppage gait, difficulty walking, knee hiking
- Key exam findings: Foot drop / dorsiflexion weakness
- Workup: EMG/NCS performed (etiology presumed related to prior spine surgery)
- Pre-brace status: Significant gait disturbance, unhappy with function
- Post-HERMES outcome:
- Seen 1–2 times post-fabrication (estimated ~1 month after delivery)
- Reported substantial improvement in walking difficulty
- No longer following with podiatric service due to satisfaction (ongoing care with pain management/spine colleagues for other issues)
- Brace worn ~6 months at time of last discussion
- Patient reports 0/10 extremity pain with use of HERMES brace
Patient 3
- Demographics: Shorter male, slightly obese
- Relevant history: Acute event – felt a “pop” in foot/ankle, 3 month history of foot/ankle pain after twisting ankle
- Primary complaints: Pain, difficulty walking, random anterior shin pain
- Key exam findings: Lack of active dorsiflexion at tibialis anterior
- Workup: MRI performed (surprisingly showed intact tibialis anterior muscle-tendon unit despite clinical appearance of rupture); EMG/NCS pending at time of discussion
- Pre-brace status: Using cane due to severe difficulty
- Post-HERMES outcome:
- First follow-up visit (recent, within past week of discussion): No longer using cane
- Pain substantially reduced
- Patient “thrilled” with brace and independence gained
General observations across cases
- All three patients reported the brace as comfortable, lightweight, and non-irritating (no digging into skin).
- Rapid functional gains (often by first follow-up visit) included loss of assistive device dependence.
- Proximal pain relief (beyond ankle) was noted in at least two patients, suggesting secondary biomechanical benefit.
Conclusions
In this small series of three patients with dorsiflexion weakness of heterogeneous etiology (multifactorial neuromuscular, post-spine surgery, and acute idiopathic), the Icarus HERMES adjustable dorsiflexion-assist AFO provided rapid, clinically meaningful improvement in gait independence and pain reduction. Elimination of cane/walker use and improved comfort were consistent themes. The brace appears particularly promising for patients who have not responded to traditional AFOs or who experience proximal compensatory pain.
Limitations include small sample size, retrospective design, lack of objective outcome measures, short/heterogeneous follow-up intervals, absence of control/comparison group, and incomplete documentation of brace specifications and fitting details. Longer-term durability, patient-reported outcome scores, quantitative gait parameters, and comparison to alternative devices (e.g., carbon-fiber energy-return AFOs or custom Arizona-style braces) remain to be evaluated.
These preliminary findings support further prospective evaluation of the HERMES AFO in patients with dorsiflexion weakness, particularly in cases of failed conservative management or as an alternative to more expensive or less tolerated devices.
