Biomechanical analysis of specific motor impairments contributing to early functional decline in adults living with HIV-1 infection : a sub-study to the Cape Winelands HAART to HEART (Prevalence)/EndoAfrica study

[摘要] ENGLISH SUMMARY : Background: HIV-1 infection has become a chronic condition. Although people living with HIV-1 infection(PLHIV) now have near-normal life expectancies, walking-related impairments remain concerning as they occur early and may lead to falls. A poor understanding remains of how movement patterns are affected due to a lack of biomechanical studies. Three-dimensional (3D) motion analysis can provide insight into movement patterns and assist in identifying a valid performance-based screening test for detecting early motor impairments in PLHIV.Aim: The aim of this research was to investigate gait and balance impairments existing in PLHIV using 3D motion analysis. It further aimed to correlate 3D analysis findings (via a gait summaryscore), as well as self-reported function and history and fear of falling, to physical performance tests which may be considered in clinical practice to screen for early functional decline in PLHIV.Methods: The research was divided into three parts:Part I presented a systematic review describing objective gait and balance impairments in PLHIV. Results contributed to the theoretical groundwork for study conceptualisation and aided in selecting clinically relevant biomechanical outcomes and performance-based tests.Part II comprised validity and reliability testing of a portable 3D gait analysis (3DGA) system, newly obtained by the motion laboratory, in 16 healthy student volunteers, as well as in eightconsecutively recruited PLHIV and eight community-matched seronegative participants (SNP). The studies determined the psychometric properties of specific 3DGA outcomes to aidappropriate data interpretation in the next phase.Part III comprised the main observational study to cross-sectionally describe keybiomechanical characteristics in 50 PLHIV relative to 50 community-matched SNP(consecutively sampled). The study was conducted in a clinical setting, and performancebased tests were assessed in addition to the 3D motion analysis. Gait analysis results, fallrelated outcomes and self-reported function were correlated to clinical test performance to identify the most valid performance-based screening test.Main results: The systematic review (Part I) revealed some agreement that PLHIV walk slower and have increased centre of pressure (COP) excursions and postural reflex latencies, particularly underchallenging conditions. No included studies used 3DGA. The validity and reliability studies (Part II) demonstrated that, with regular recalibration, the 3DGA system reliably measures gait biomechanics in SNP and PLHIV, except for four discrete angles. The system/model highly compares to the reference model after accounting for modelling differences. The field study(Part III) revealed that the gait of PLHIV (median age: 36.61 years) was significantly slowed and rigid relative to SNP (median age: 31.10 years). This pattern manifested when walking ata usual pace or when performing a dual task. Dual task walking further revealed joint range of motion (ROM) changes at the hip and knee in a distal-to-proximal pattern-shift. PLHIV also demonstrated increased COP excursion in dual task single-leg stance. PLHIV weresignificantly slower in completing the Five-Times Sit-To-Stand (5STS) Test. Slowed sit-tostand was significantly related to gait rigidity, worse self-reported function, and fear of falling.Conclusion: Relatively young PLHIV present with biomechanical gait and balance impairments that resemble patterns noted in elders, especially under dual task conditions. The 5STS test isrecommended as a valid clinical screening test. These findings improve understanding of movement impairments in PLHIV and highlight the need for early screening. Further research is needed to determine whether the 5STS test predicts falls, and whether the impairmentsnoted in PLHIV are reversible. Early identification and rehabilitation can reduce healthcare utilisation needs in PLHIV.

[发布机构] Stellenbosch University