Original Article Video based measurement of sagittal range of spinal motion in young and older adults q Yi-Liang Kuo a , Elizabeth A. Tully b, * , Mary P. Galea b a Department of Physical Therapy, Shu Zen College of Medicine and Management, Kaohsiung County 821, Taiwan b School of Physiotherapy, Faulty of Medicine, Dentistry and Health Sciences, The University of Melbourne, 200 Berkeley Street, Parkville, Victoria 3010, Australia article info Article history: Received 23 May 2008 Received in revised form 20 November 2008 Accepted 3 December 2008 Keywords: Spine Measurement Range of motion Aging abstract A revised model of skin marker placement with the two-dimensional (2D) PEAK Motus system was used to investigate the effect of aging on sagittal range of spinal motion. Twenty-four healthy young adults and twenty-two healthy older adults were videotaped while performing the movements of flexion and extension in each spinal region d cervical, thoracic and lumbar spine. Alternative movement tests that may allow a greater range of motion (ROM) for thoracic extension and lumbar flexion were also inves- tigated. Older adults demonstrated significantly decreased flexion/extension ranges in the cervical, thoracic and lumbar spine. The movement of cat-stretch in the all-fours position allowed greater thoracic extension, and the movement of toe-touch in standing permitted greater lumbar flexion. This study provides reference data for sagittal ranges of spinal motion in healthy young and older adults as measured by a 2D imaged-based system. The sagittal model of skin marker placement used in this study can have a broader application for ROM measurement in the clinical setting using a digital camera and freely downloadable software. Ó 2009 Elsevier Ltd. All rights reserved. 1. Introduction Knowledge of the expected range of motion (ROM) in healthy subjects provides the basis for assessment and for establishing appropriate treatment goals in clinical practice. Radiographic methods are considered the ‘gold standard’ for ROM measurement (Portek et al., 1983), however the risk of radiation exposure limits its use. Previous studies agree that increasing age is associated with decreased spinal motion, however the descriptive information provided from simple clinical tools (Loebl, 1967; Moll and Wright, 1971; Kuhlman, 1993) has frequently been jeopardized by measurement issues. For example, the Schober tape measure method (Moll and Wright, 1971) provides an index of lumbar movement (in cm) reported as unreliable (Portek et al., 1983; Miller et al., 1992). Use of a single inclinometer positioned over a specific spinous process (e.g. T12/L1) is gravity referenced, and thus only indicates the orientation of the body segment in space, with the angle being dependent on the position of the more caudal body segments. The dual inclinometer method provides more valid and accurate measurement for lumbar flexion (Loebl, 1967; Saur et al., 1996), however the reliability of measurement for lumbar exten- sion has shown to be low (Merritt et al., 1986; Dillard et al., 1991). In contrast, a motion analysis system that tracks the displace- ment of reference markers attached to the skin over relevant bony landmarks can provide more reliable and accurate measurement of human movement. However, previous ROM studies have been compromised by problematic models of marker placement. For example, Hu et al. (2006) placed markers over a swimming cap and a sleeveless shirt to measure ROM in the cervical spine. Possible stretch or slide of the cap and clothes as well as skin movement errors likely influenced the validity and reliability of the data. In addition, the cervical spine was measured as a whole without acknowledging the functional differences between the upper and lower cervical regions. Also, in most surface-based studies infor- mation regarding ROM has been limited to a single spinal region (Dvorak et al., 1995; McGill et al., 1999; Sforza et al., 2002; Wu et al., 2007), with no attempt to determine the mobility of adjacent regions in this functionally interdependent chain of joints. Another factor influencing the ROM is test movement. The clinical tests for lumbar flexion and extension are often performed in standing, and patients with balance problems may have diffi- culty achieving full lumbar extension. Similarly patients attempting thoracic extension in sitting tend to lean backwards from the hips so that the full available thoracic movement is not achieved. An q This research was carried out as part of a PhD by Yi-Liang Kuo at The University of Melbourne. * Corresponding author. Tel.: þ61 3 8344 4171; fax: þ61 3 8344 4188. E-mail address: e.tully@unimelb.edu.au (E.A. Tully). Contents lists available at ScienceDirect Manual Therapy journal homepage: www.elsevier.com/math 1356-689X/$ – see front matter Ó 2009 Elsevier Ltd. All rights reserved. doi:10.1016/j.math.2008.12.006 Manual Therapy 14 (2009) 618–622