Detection of joint bleeding symptoms in Haemophilia with the Noraxon system – pilot study

Introduction: Haemophilic joint changes need to be identified and halted as early and complete as possible.^1,2 Biomechanical analysis can help complete the existing diagnostic measures by detecting joint changes prior to graphic evidence and under weight-bearing conditions, which is relevant in finding the complex movement disorders associated with Haemophilia as early in their development as possible.³

Method: One biomechanical analysis tool is the Noraxon system, which employs validated sensing methods, including inertial measurement units (IMUs), electromyography (EMG), and pedobarography and was already used in over 400 peer-reviewed medical publications on other conditions.⁴ For this study, we measured side-to-side differences in muscle activation via EMG. The objective of this study was to ascertain whether there is a correlation between the findings derived from the Noraxon system and the Haemophilia Early Arthropathy Detection with Ultrasound system (HEAD-US)⁵ and the Haemophilia Joint Health Score (HJHS).⁶

Results: The study included 61 male patients with a mean age of 22 years (range 6 to 61 years). Of these, 55 had haemophilia A and 6 had haemophilia B. 43 were classified as either severe and 18 as moderate cases. 36.2% of the respondents indicated that they did not experience any joint complaints. Among those who did, the most frequently reported joints were the knees, with 15.6% of respondents indicating discomfort in both the right and left knees. Ankle complaints were reported by 10.8% of respondents, while elbow complaints were reported by 4.8% (right) and 6.2% (left). The average HJHS was 1.9 and the average HEAD-US was 1.8 - with 0=none and 32/31=maximum joint damage for HJHS/HEAD-US. For both scores, younger groups generally had lower Head-US scores, with higher scores more common in older age groups. Our analysis identified 12 moderate but significant correlations for the five indicators. 1. HJHS 2. HEAD-US 3. Joint complaints and EMG lateral differences in 4. standing and 5. The analysis revealed a correlation between the swinging phases of gait. Our analysis identified a correlation between the HJHS and HEAD-US, as well as between HEAD-US and HJHS. Furthermore, we noted a correlation between the lateral differences in EMG and joint complaints, as well as EMG. These findings are presented in [Fig. 2] of the attachment. [Fig. 1] provides a comprehensive illustration of the correlation between the HJHS- and the HEAD-US-Score.

Fig. 2  Correlations Biomechanical Analysis Men GTH 2025

Fig. 1  Biomech study men GTH 2015

Conclusion: In light of the aforementioned results, we believe that the biomechanical analysis is an effective method for identifying joint issues in men with haemophilia. However, the study group was relatively small, which limited the ability to fully exploit the wide range of analysis options available through the Noraxon system. We therefore recommend further studies conducted under the supervision of experienced biomechanists.

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Artikel online veröffentlicht:
13. Februar 2025