Hurley, M.V., Rees, J. and Newham, D.J. (1998) Quadriceps function, proprioceptive acuity and functional performance in healthy young, middle-aged and elderly subjects. Age and Ageing, 27, 55-62. http://dx.doi.org/10.1093/ageing/27.1.55
 Jochanan, S., Robert, H.R., Aaron, C., Eliana, E.M. and Jeremy, M.J. (2009) Physical activity, function, and longevity among the very old. Archives of Internal Medicine, 169, 1476-1483. http://dx.doi.org/10.1001/archinternmed.2009.248
 Tinetti, M.E. and Williams, C.S. (1998) The effect of falls and fall injuries on functioning in community-dwelling older persons. Journal of Gerontology: Medical Sciences, 53, 112-119. http://dx.doi.org/10.1093/gerona/53A.2.M112
 Peat, G., McCarney, R. and Croft, P. (2001) Knee pain and osteoarthritis in older adults: A review of community burden and current use of primary health care. Annals of the Rheumatic Diseases, 60, 91-97. http://dx.doi.org/10.1136/ard.60.2.91
 Tennant, A., Fear, J., Pickering, A., Hillman, M., Cutts, A. and Chamberlain, M.A. (1995) Prevalence of knee problems in the population aged 55 years and over: Identifying the need for arthroplasty. British Medical Journal, 310, 1291-1293. http://dx.doi.org/10.1136/bmj.310.6990.1291
 Ikushima, H., Hidaka, M. and Ikeda, K. (1994) The relationship between activities of daily living and pain and/or muscle strength in patients with osteoarthritis of the knee. Physiotherapy, 21, 347-350.
 Murray, M.P., Duthie, E.H., Gambert, S.R., Sepic, S.B. and Mollinger, L.A. (1985) Age-related differences in knee muscle strength in normal women. Journal of Gerontology, 40, 275-280. http://dx.doi.org/10.1093/geronj/40.3.275
 Hunter, G.R., Treuth, M.S., Weinsier, R.L., Kekes-Szabo, T., Kell, S.H., Roth, D.R. and Nicholson, C. (1995) The effects of strength conditioning on older women’s ability to perform daily tasks. Journal of the American Geriatrics Society, 43, 756-760.
 Corrigan, D. and Bohannon, R.W. (2001) Relationship between knee extension force and stand-up performance in community-dwelling elderly women. Archives of Physical Medicine and Rehabilitation, 82, 1666-1672. http://dx.doi.org/10.1053/apmr.2001.26811
 Oya, Y., Nakamura, M., Tabata, E., Morizono, R., Mori, S., Komuro, Y. and Horikawa, E. (2008) Fall risk assessment and knee extensor muscle activity in elderly people. Journal of Geriatrics, 45, 308-314.
 Zaharni, K.S. and Bakheit, A.M. (2002) A study of the gait characteristics of patients with chronic osteoarthritis of the knee. Disability and Rehabilitation, 24, 275-280. http://dx.doi.org/10.1080/09638280110087098
 Zoltan, B., Robert, P., Arpad, I., Rita, M.K. (2006) The influence of walking speed on gait parameters in healthy people and in patients with osteoarthritis. Knee Surgery, Sports Traumatology, Arthroscopy, 14, 612-622. http://dx.doi.org/10.1007/s00167-005-0005-6
 Mc Alindon, T.E., Snow, S., Cooper, C. and Dieppe, P.A. (1992) Patterns of osteoarthritis of the knee joint in the community: The importance of the patellofemoral joint. Annals of the Rheumatic Diseases, 51, 844-849. http://dx.doi.org/10.1136/ard.51.7.844
 Urwin, M., Symmons, D., Allison, T., Brammah, T., Bus- by, H. and Roxby, M. (1998) Estimating the burden of musculoskeletal disorders in the community: The comparative prevalence of symptoms at different anatomical sites, and the relation to social deprivation. Annals of the Rheumatic Diseases, 57, 649-655. http://dx.doi.org/10.1136/ard.57.11.649
 Demura, S., Sato, S., Minami, M., Kobayashi, H., Noda, Y., Matsuzawa, J., Kobayashi, K. and Aoki, J. (2000) Development of ADL index for older community people. Japanese Journal of Physical Fitness and Sports Medi- cine, 49, 375-384.
 Sato, S., Demura, S., Matsuzawa, J., Noda, Y., Miyaguchi, H., Tada, N., Kobayashi, H., Goshi, F., Minami, M. and Sugano, N. (2000) Development of ADL index for heal- thy older persons: Proposal of useful ADL items and their scales. Journal of Physical Education Health and Sport Sciences, 45, 472-488.
 Bellamy, N., Buchanan, W.W., Goldsmith, C.H., Campbell, J. and Stitt, L.W. (1988) Validation study of WO- MAC: A health status instrument for measuring clinically important patient relevant outcomes to antirheumatic drug therapy in patients with osteoarthritis of the hip or knee. Journal of Rheumatology, 15, 1833-1840.
 Hashimoto, H., Hanyu, T., Sledge, C.B. and Lingard, E.A. (2003) Validation of a Japanese patient-derived outcome scale for assessing total knee arthroplasty: Comparison with Western Ontario and McMaster Universities osteoarthritis index (WOMAC). Journal of Orthopaedic Science, 8, 288-293. http://dx.doi.org/10.1007/s10776-002-0629-0
 Astephen, J.L., Deluzio, K.J., Caldwell, G.E. and Dunbar, M.J. (2008) Biomechanical changes at the hip, knee, and ankle joints during gait are associated with knee osteoarthritis severity. Journal of Orthopaedic Research, 26, 332-341. http://dx.doi.org/10.1002/jor.20496
 Sugiura, H. and Demura, S. (2012) Effect of subjective knee-joint pain on the laterality of knee extension strength and gait in elderly women. Archives of Gerontology and Geriatrics, 54, 366-369. http://dx.doi.org/10.1016/j.archger.2011.04.024
 Oliveria, S.A., Felson, D.T., Cirillo, P.A., Reed, J.I. and Walker, A.M. (1999) Body weight, body mass index, and incident symptomatic osteoarthritis of the hand, hip and knee. Epidemiology, 10, 161-166. http://dx.doi.org/10.1097/00001648-199903000-00013
 Yoshimura, N., Nishioka, S., Kinoshita, H., Hori, N., Ni- shioka, T., Ryujin, M., Mantani, Y., Miyake, M., David, C. and Cyrus, C. (2004) Risk factors for knee osteoarthritis in Japanese women: Heavy weight, previous joint injuries, and occupational activities. Journal of Rheumatology, 31, 157-162.
 Spector, W.D., Katz, S., Murphy, J.B. and Fulton, J.P. (1987) The hierarchical relationship between activities of daily living and instrumental activities of daily living. Journal of Chronic Diseases, 40, 481-489. http://dx.doi.org/10.1016/0021-9681(87)90004-X
 Kim, H.S., Matsuura, Y., Tanaka, K. and Inagaki, A. (1993) Facyorial structure and establishment of a test battery to evaluate ability of daily living activity in the elderly. Journal of Physical Education Health and Sport Sciences, 38, 187-200.