Protocol Paper1000 Norms Project: protocol of a cross-sectional study cataloging human variation
Introduction
Evidenced-based practice is currently focused on patient-centred outcomes [1]. The ability of outcome measures to inform clinical decision-making is dependent on the development of reference values representative of the healthy population. In physiotherapy and other fields of healthcare, an understanding of physical performance and the range of normal variation is essential, as decisions regarding diagnosis, management and prevention of musculoskeletal and neurological disorders are frequently based on comparison with healthy or ‘normal’ values. To prescribe interventions for improving quality of care, we must first establish a set of clinically relevant measures [2], [3]. To evaluate the impact of physical therapies and to communicate clearly and succinctly with colleagues, valid and reliable data are required [4]. At the patient level, a normative reference database provides important information regarding diagnosis, symptom risk and status change in response to treatment, allowing their progress to be more closely assessed and treatment effectiveness more clearly determined [5]. Greater understanding of physical performance and normal variation in the healthy population and identifying age-related changes in musculoskeletal and neurological function will assist outcome measure development for clinical trials.
Currently limited comprehensive datasets exist detailing the range of normal variation in healthy individuals. Previous studies establishing reference values have typically comprised a limited number of measures and have frequently involved young, disease-free adults, reducing the applicability of the reference data to the wider population [6]. Furthermore, reference values published in restricted access journals can render such data inaccessible to many researchers and most clinicians. Reference value datasets do exist for a select range of measures, such as grip strength [7], range of motion [8], strength [9], and gait [10], however there is no single resource containing reference values for males and females across the lifespan for musculoskeletal and physical performance measures. Therefore, there is an immediate need for reference values that are representative of the healthy normal population and presented in a manner that can be accessed by all [11]. This single resource will be a central point of reference for physiotherapists, clinical researchers and other health professionals to access reference data, including details pertaining to reliability, validity and assessment protocols. The 1000 Norms Project reference dataset will stimulate high impact research activity, enabling robust evaluations with sensitive outcome measures, analysis of clinically relevant subgroups and a greater understanding of the interactions and associations between different musculoskeletal and neurological measures of health. The need for standardised measures has also been identified by the National Institutes of Health (NIH) who developed the NIH Toolbox to advocate for standard assessment of neurological and behavioural function [12]. The NIH Toolbox is a set of standard measures within the domains of cognition, motor function, sensory function and emotional health. The 1000 Norms Project will contribute to this international focus on accurate outcomes by producing a large reference dataset of standardised musculoskeletal and neurological measures collected in a cohort of healthy individuals across the lifespan.
Research focusing on ageing and lifestyle has demonstrated that habitual physical activity interacts with ageing and has the capacity to modulate musculoskeletal health and functional performance [13]. The influence of epigenetic factors, notably physical activity habits on muscle phenotypes in the elderly, suggests that genotype is possibly the strongest candidate to explain variance among muscle phenotypes [14]. Alpha-actinin-3 (ACTN3) has been identified as one of many genes contributing to genetic variation in muscle performance and adaptation to exercise. ACTN3 has been shown to have a beneficial effect on the function of skeletal muscle in generating muscle force [15], [16]. Several cross-sectional studies indicate an association between athletic performance and ACTN3 genotype [16], [17], [18], however participants in these studies were highly trained athletes and may not be representative of the general population. Hagberg et al. [19] states that whilst there is evidence that ACTN3 acts as a contributor to muscle trait variation, the importance in the untrained population remains unclear. Further studies are needed to establish the influence of ACTN3 on functional abilities in elderly populations, for instance, to target individuals who may be more susceptible to the effects of sarcopenia and require specific interventions [20], [21]. The 1000 Norms Project will contribute to the understanding of the genetic contribution to human phenotype by investigating the association of ACTN3 genotype with the physical performance items related to strength and power in individuals across the lifespan.
The primary aim of the 1000 Norms Project is to generate a wide ranging database of musculoskeletal and neurological reference values in a cohort of 1000 healthy individuals aged 3 to 100 years. A secondary aim is to develop predictive equations adjusted for factors such as age and gender for each individual measure.
Section snippets
Overview of the study design
In 2012, the 1000 Norms Project Consortium, an interdisciplinary multi-institutional collaboration of researchers, clinicians and higher degree students, designed the 1000 Norms Project over a four stage process which included: (1) the establishment of working parties, (2) a comprehensive review of the definition of ‘normal’, (3) identifying viable sampling and recruitment strategies, and (4) selection of clinically relevant patient-centred musculoskeletal and neurological items to be collected
Discussion
Knowledge of normal variation of healthy individuals is essential to identify deviation from normal and to evaluate responses to physiotherapy and other treatments. Through improving our understanding of the normal range of healthy variation, the 1000 Norms Project will assist outcome measure development and greatly contribute to future patient-centred outcomes research. Whilst some normative reference values exist, there is a lack of comprehensive data cataloguing the physical performance and
Acknowledgements
John Eisenhuth and Ray Patton for providing technical assistance, Melissa Mandarakas for photography, Dr Peter Houweling and Fleur Garton for development and testing of the DNA sampling procedure and Professor Jennifer Peat for statistical advice.
Ethical approval: The study is approved by The University of Sydney Human Research Ethics Committee, approval number 2013/640.
Funding: This Project is supported by the National Health and Medical Research Council of Australia (NHMRC, #1031893),
References (34)
Evaluation of physiotherapy by measuring the outcome
Physiotherapy
(2000)- et al.
Normal walking speed: a descriptive meta-analysis
Physiotherapy
(2011) - et al.
Assessment of neurological and behavioural function: the NIH Toolbox
Lancet Neurol
(2010) - et al.
ACTN3 genotype is associated with human elite athletic performance
Am J Hum Genet
(2003) - et al.
OARSI recommended performance-based tests to assess physical function in people diagnosed with hip or knee osteoarthritis
Osteoarthr Cartilage
(2013) - et al.
Selection bias from sampling frames: telephone directory and electoral roll compared with door-to-door population census: results from the Blue Mountains Eye Study
Aust NZ J Publ Heal
(1997) - et al.
Standards should be applied in the prevention and handling of missing data for patient-centered outcomes research: a systematic review and expert consensus
J Clin Epidemiol
(2014) - et al.
Getting the methods right—the foundation of patient-centered outcomes research
N Engl J Med
(2012) - et al.
A call for evidence-based quality measures: a goal worthy of pursuit
Nat Clin Pract Rheumatol
(2007) - et al.
Clinimetrics in rehabilitation medicine: current issues in developing and applying measurement instruments 1
J Rehabil Med
(2005)
Measurement of health outcomes in the clinical setting: applications to physiotherapy
Physiother Theory Pract
The evolution of the reference value concept
Clin Chem Lab Med
Revised normative values for grip strength with the Jamar dynamometer
J Peripher Nerv Syst
Range of motion measurements: reference values and a database for comparison studies
Haemophilia
Isokinetic and isometric muscle strength in a healthy population with special reference to age and gender
Acta Psychol
Normality: the unreachable star?
Clin Chem Lab Med
Association between changes in habitual physical activity and changes in bone density, muscle strength, and functional performance in elderly men and women
J Am Geriatr Soc
Cited by (45)
Is there a relationship between sagittal cervical spine mobility and generalised joint hypermobility? A cross-sectional study of 1000 healthy Australians
2021, Physiotherapy (United Kingdom)Citation Excerpt :Active ranges of cervical flexion and extension were measured using a standardised protocol [21], the method demonstrating good reliability [28]. Pilot testing by two experienced examiners, physiotherapists with more than 10 years of clinical experience, demonstrated excellent inter-rater reliability for Beighton scoring and CROM measures (all ICC > 0.75) [21]. Accordingly, either one of the examiners assessed the CROM of each participant.
Paediatric Podiatry
2020, Neale’s Disorders of the Foot and AnkleEffects of moderate mountain hiking and balneotherapy on community-dwelling older people: A randomized controlled trial
2019, Experimental Gerontology