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Summary

HeadX Kross and HeadX Duo are both head-mounted crosshair laser systems designed for cervical proprioception assessment and rehabilitation.

HeadX Kross delivers real-time visual feedback through the laser — clinicians and patients can see head position and movement immediately, in all three planes.

HeadX Duo does everything Kross does, and adds objective digital measurement: movement is captured, quantified, and stored in the companion application, session by session.

Both support the same clinical indications and the same 70-exercise programme. The decision between them comes down to whether you need to measure and document movement as well as see it.

At a glance

  HeadX Duo

Immediate visual feedback on head position

Feedback across all three planes (rotation, tilt, flexion/extension)

See compensatory head tilt in real time

Full 70-exercise rehabilitation programme

Suitable for clinic and home use

Used in concussion, whiplash, vestibular, and neck pain rehabilitation

Objective digital measurement of head and neck movement

Active cervical range of motion assessment with recorded output

Joint position error testing with automatic angular capture

Session history and progress tracking over time

Exportable data for clinical reporting or research

Companion iOS / Android application

Suitable for research and clinical audit

HeadX Kross: See the Movement

The Kross makes head movement visible. Its patented crosshair laser projects a clear, real-time display of the patient's head position onto a wall-mounted target — showing not just whether they are on target, but whether they are compensating with a tilt they cannot feel. That roll-plane feedback is something single-point laser systems cannot provide, and it matters clinically in vestibular rehabilitation, post-concussion sensorimotor retraining, and any presentation where patients have learned to mask position error with head tilt.

The practical effect is that patients can self-correct in real time. They do not have to wait for the clinician to tell them what they did wrong — they can see it, adjust, and try again. This accelerates motor learning and keeps sessions engaging. Clinicians can observe movement quality, symmetry, and accuracy across all planes simultaneously.

For many clinical contexts, that immediate visual loop is precisely what is needed. The 70-exercise HeadX programme is built around it. The Kross is an effective, accessible tool for delivering that programme in clinic and at home.

Kross works particularly well when:

The goal is retraining, not measuring. Where the rehabilitation plan centres on structured exercise and progressive motor retraining — building accuracy, consistency, and automaticity in cervical movement — the Kross provides everything required. The visual feedback loop is the intervention; the Kross delivers it clearly and immediately.

Patients are doing exercises at home. The Kross gives patients the same quality of visual feedback between sessions that they get in clinic, supporting consistent practice without relying on a companion application.

Speed and simplicity matter. In a busy clinic, the Kross is fast to deploy per session. There is no session to configure and no Bluetooth to connect. For clinicians managing high appointment volumes, that efficiency has real operational value.

Visual JPET is your standard assessment. If you use the established wall-and-target protocol for cervical joint position error testing — reading the laser position manually and calculating angular error — the Kross supports that workflow fully. The published clinical reference values are based on exactly this approach.

HeadX Duo: See It, Measure It, Prove It

The Duo does everything the Kross does — the crosshair laser is identical — and adds a layer that the Kross cannot provide: an objective, recorded measurement of what actually happened during the session.

Every movement is captured as angular data across all three planes. Active range of motion is measured and stored. Joint position error is calculated automatically rather than read from a chart. Session results are held in the companion application, where they can be compared against previous sessions, reviewed by other clinicians, or exported for reporting. Over time, this builds a longitudinal picture of how a patient's head and neck control is changing — a picture based on data rather than clinical impression.

This matters in a growing number of contexts. Concussion management increasingly requires documented, objective evidence of cervical function. Return-to-performance decisions carry real consequences and are easier to defend when they rest on data. Medico-legal cases, multi-disciplinary team settings, and research environments all benefit from a session record that is reproducible and auditable. The Duo provides that record without changing the clinical workflow that clinicians are already familiar with from the Kross.

Duo works particularly well when:

You need to show change, not just observe it. There is a meaningful clinical difference between noting that a patient's movement looks better and being able to show that their JPET error has reduced from 6.2° to 2.8° over eight weeks, or that their active rotation has increased by 14° since the first session. The Duo makes the second statement possible.

Complex or high-stakes cases require documentation. In post-concussion care, return-to-sport assessments, or cases with medico-legal dimensions, objective records carry weight that observation cannot. The Duo produces a session-by-session data trail that can be reviewed, shared with colleagues, or presented as evidence of clinical progress.

You are working in sport, military, or performance environments. High-performance settings demand precision. Baseline profiling, post-incident assessment, and return-to-performance comparison all benefit from the ability to capture and compare exact movement data across time points. Subtle deficits that are invisible to observation are detectable in the data.

Research or service evaluation is part of your work. The Duo generates exportable session data that can be used in outcome analysis, service audits, or research projects. For clinicians contributing to the evidence base in cervical rehabilitation or sensorimotor assessment, this is a practical operational difference.

You want JPET to be automatic. With the Kross, JPET requires reading the laser position from the target chart at the end of each trial and recording the result manually. With the Duo, angular error is captured and calculated automatically throughout the repositioning task, removing rater variability and reducing assessment time.

The Wallchart and Exercise Programme: Designed for Both Devices

Both Kross and Duo are designed to work with the HeadX wallchart — the wall-mounted target system that serves as the reference point for all laser-guided exercises and JPET assessment. The wallchart provides the concentric target grid that makes head position visible during exercises and gives the clinician a structured reference for measuring JPET error distance. It is included with both devices and remains the foundation of the laser-guided workflow regardless of which device is in use.

Alongside the wallchart, HeadX provides a free 70-exercise rehabilitation programme covering four clinical chapters: cervical proprioception and joint position sense, range of motion and motor control, gaze stabilisation and head-eye coordination, and head and neck stability. The programme is structured to support progressive rehabilitation across all common indications — from early-stage post-concussion and whiplash management through to performance-level sensorimotor training — and each exercise is delivered with clear guidance on setup, movement, and progression.

The exercise programme is free and accessible to all patients and clinicians, independently of which device is being used. Kross users follow the exercises using the laser and wallchart for real-time visual feedback. Duo users follow the same exercises with the addition of digital movement data captured in the companion application. The session content is identical; the Duo simply adds measurement to it.

For clinicians new to HeadX, the exercise programme is the natural starting point for understanding how both devices are used in practice. For patients, it provides the structured home programme that makes the Kross effective as a between-session rehabilitation tool.

The wallchart and exercise programme can be found at headx.co.uk/pages/exercises.

Using Kross and Duo Together

For many clinics, the most effective approach is not choosing between the two devices — it is using both in combination, each where it works best.

The Duo handles in-clinic assessment and rehabilitation. At the start of a course of treatment, it establishes an objective baseline: active cervical range of motion, JPET error values, and movement symmetry across planes. As treatment progresses, the same measurements are repeated. The data shows, session by session, whether the patient is improving and in which planes deficits remain. Clinical decisions — when to progress an exercise, when to investigate further, when to discharge — are made on the basis of numbers rather than impression. In complex or high-stakes cases, that data record also provides the documentation that MDT colleagues, insurers, or return-to-sport panels may require.

The Kross handles home-based rehabilitation between sessions. Rather than asking patients to wait passively for their next clinic appointment, the Kross gives them an effective tool to continue working independently. Paired with the free HeadX exercise programme — a structured 70-exercise library covering proprioception, gaze stabilisation, head stability, and sensorimotor retraining — patients can follow a clinician-prescribed progression at home with the same quality of visual feedback they receive in clinic. Adherence is higher when patients have a clear exercise plan and a device that makes their performance visible. The Kross provides both.

The clinical logic is straightforward. The Duo generates the objective evidence that guides treatment. The Kross extends the reach of that treatment into the patient's daily life, at a price point that makes home loan or purchase practical. Together, they create a continuous rehabilitation pathway rather than a series of isolated clinic appointments.

Clinics that work this way typically keep one or more Duo devices for in-clinic use and issue Kross devices to patients for the duration of their home programme. The two devices share the same crosshair laser system and the same exercise library, so there is no discontinuity in the patient's experience between clinic and home.

Frequently Asked Questions

Can both devices be used for joint position error testing?
Yes. Both support the established head-mounted laser JPET protocol. With the Kross, the clinician reads the laser position on the target chart and records the angular deviation manually. With the Duo, angular error is captured automatically and stored digitally, reducing assessment time and rater variability. The clinical threshold of 4.5° for impaired cervical proprioception (Revel et al., 1991) applies to both methods.

Is HeadX Duo a replacement for HeadX Kross?
No. The Duo extends the capability of the Kross by adding digital measurement. HeadX designs the two devices as complementary tools within the same clinical system. Many clinics use Kross for routine exercise delivery and Duo for formal assessment, complex cases, or research.

Which device is better for home use?
Both can be used at home. The Kross is simpler for patients who are less familiar with technology, as it requires no application. The Duo can equally be used at home and gives patients visibility of their own progress in the application, which some find motivating. The right choice depends on the patient and their confidence with the companion app.

Can a clinic start with Kross and add Duo later?
Yes. Both devices share the same clinical workflow. Clinicians familiar with the Kross will find the Duo immediately intuitive — the session structure and laser guidance are identical. The Duo adds measurement without requiring any change in clinical approach.

Is the crosshair laser the same on both devices?
Yes. Both devices project the same patented crosshair laser. The roll-plane tilt feedback that distinguishes HeadX from single-point laser systems is present on both Kross and Duo.

What conditions are both devices indicated for?
Both are indicated across the same clinical range: whiplash-associated disorders, post-concussion cervical involvement, chronic neck pain, vestibular dysfunction, cervicogenic dizziness, cervicogenic headache, neurological conditions affecting head and neck control, and high-performance sensorimotor screening. The clinical indication does not determine which device is appropriate — the need for documented measurement data does.

Does HeadX Duo require a smartphone or tablet?
Yes. The Duo connects to the HeadX companion application via Bluetooth on iOS or Android. The application is required for measurement, data storage, and session review. The laser functions for exercise delivery without the app, but measurement capability requires it.

Which device do research institutions use?
Where research requires exportable, reproducible movement data, the Duo is the appropriate tool. Where a study involves laser-guided exercise as an intervention without data capture, the Kross is sufficient. Both have been used in clinical and research settings.