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HeadX Kross and Duo

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

HeadX Kross makes head position and orientation visible. Its crosshair laser projects onto a wall-mounted target, showing pitch, yaw and roll so the person and clinician can observe target error and unwanted tilt.

The immediate visual feedback can be used during clinician-selected motor-control, gaze and head-movement exercises. Kross does not record digital movement data; any Joint Position Error value is measured and documented manually using a consistent wall-and-target protocol.

Kross works particularly well when:

The goal is visual feedback rather than digital recording. The person can see the laser response during a structured exercise while the clinician observes movement quality and selects progression.

Exercises continue at home. After fitting, instruction and confirmation of suitability, Kross can provide the same form of visual feedback without a companion application.

Speed and simplicity matter. Kross has no Bluetooth connection or digital session to configure.

Manual JPET is your chosen protocol. The clinician reads laser displacement on a target and converts it to angular error using the test distance. Results should be interpreted with the full assessment rather than against a single universal cut-off.

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. Kross supports a wall-and-target protocol in which displacement is read and recorded manually. Duo records angular repositioning error digitally in the companion app. A mean error of approximately 4.5° has historically been used as a reference in some head-to-neutral protocols, but it is not a universal diagnostic, recovery or discharge threshold.

Is HeadX Duo a replacement for HeadX Kross?
No. Duo adds inertial sensing and digital recording to the crosshair-laser feedback available from Kross. The appropriate device depends on whether the clinician needs visual feedback alone or recorded measurement data.

Which device is better for home use?
Either may be used at home after appropriate fitting and instruction. A clinician should confirm suitability and specify the exercises, dose and progression. Duo requires the companion app for measurement and session review.

Can a clinic start with Kross and add Duo later?
Yes. The devices share crosshair-laser feedback, while Duo adds app-connected digital measurement.

Is the crosshair laser the same on both devices?
Both devices use HeadX crosshair-laser feedback across pitch, yaw and roll.

In which clinical settings might the devices be used?
A suitably qualified clinician may select them where cervical movement, head-repositioning, gaze-control or head-control tasks are relevant to the assessment or rehabilitation plan. They do not diagnose concussion, vestibular disorders, neck pain or neurological conditions.

Does HeadX Duo require a smartphone or tablet?
Yes. 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 can provide visual feedback without the app.

Which device is suitable for research?
That depends on the protocol. Duo is intended where recorded and exportable movement data are required; Kross may suit laser-guided exercise or manually recorded target tasks. Researchers should define validation, calibration and data-handling requirements before selecting a device.