As we age, we generally experience a progressive decline in the ability to use our arms and hands for normal daily activities such as using cutlery to cut food, brushing our teeth and buttoning up a shirt (Shumway-Cook & Woollacott, 2016). The ability to complete everyday activities with our upper extremities relies on a complex interplay of sensorimotor capabilities such as strength, sensation, fine motor control and coordination (Lord & Ward, 1994). While a deficit in one or more of these capabilities is well documented in specific medical and neurological conditions, such as stroke and multiple sclerosis, impairments are also common in older people without a specific medical condition (Wolff et al., 2002). A framework that can assess the capacity of the various capabilities that are critical for optimal upper limb function could provide a more precise measurement of impairment levels, offering assistance for guiding and evaluating interventions (Lord et al., 2016).
Here we propose the Upper Limb Physiological Profile Assessment (PPA). Based on the original PPA (Lord et al., 1991) designed for the lower limb, the Upper Limb PPA provides a battery of 13 different clinical tests that measure the various physiological systems that are hypothesised to contribute to adequate function in the upper extremities. These include measures of muscle strength, unilateral movement and dexterity, position sense, sensation, bimanual coordination, arm stability and functional task performance.
The primary aim of the study was to provide a normative database for each of the tests based on age and sex. Other aims of the study were to determine the reliability of each test, and to explore whether test performance changed with increasing age and whether there were differences between sexes.
WHAT DID WE FIND?
Age- and sex-normative values were established for each of the 13 tests within the upper limb PPA based on a sample of 367 participants (172 males and 195 females) aged 20–95 years. Test-retest reliability ranged from good to excellent (intra-class correlation coefficients 0.65–0.98) for all but the test of position sense. Twelve of the tests showed a decline in performance with increasing age, while 10 revealed differences in performance between males and females. Furthermore, 8 of the tests discriminated between older people (65 years and over) with and without self-reported upper limb functional limitations.
SIGNIFICANCE AND IMPLICATIONS
By establishing a normative database, the study provides an important reference range for future studies investigating upper limb PPA test performance in clinical groups. Additionally, it may help to identify undiagnosed motor impairments in the general population. In conclusion, the tests within the upper limb PPA are simple and sufficiently reliable to detect motor impairments in people with compromised function of their upper extremities, and they can be used to evaluate the effectiveness of interventions aimed to improve upper limb function. Our publication contains a full description of the tests, the reason for choosing them, and data from all participants.
Ingram LA, Butler AA, Walsh LD, Brodie MA, Lord SR, Gandevia SC. The upper limb Physiological Profile Assessment: Description, reliability, normative values and criterion validity. PLoS One 14: e0218553, 2019.
Lord SR, Clark RD, Webster IW. Postural stability and associated physiological factors in a population of aged persons. J Gernotol 45: M69–M76, 1991.
Lord SR, Ward JA. Age-associated differences in sensorimotor function and balance in community dwelling women. Age Ageing 23: 452–460, 1994.
Lord SR, Delbaere K, Gandevia SC. Use of a physiological profile to document motor impairment in ageing and in clinical groups. J Physiol 594: 4513–4523, 2016.
Shumway-Cook A, Woollacott MH. Motor Control: Translating Research into Clinical Practice. 5th ed USA: Lippincott Williams & Wilkins; 2016.
Wolff JL, Starfield B, Anderson G. Prevalence, expenditures, and complications of multiple chronic conditions in the elderly. Arch Intern Med 162: 2269–2276, 2002.
Lewis Ingram is a PhD candidate at Neuroscience Research Australia. His research investigates the feasibility of a physiological profiling approach to quantifying upper limb motor impairment in the general population and in specific neurological conditions, including stroke, Parkinson’s disease and multiple sclerosis. You can learn more about Lewis and his research here: https://www.neura.edu.au/staff/lewis-ingram/.