This Article Abstract Full Text (PDF) Services Download to citation manager Citing Articles Citing Articles via HighWire PubMed PubMed Citation

Grip Strength, Postural Control, and Functional Leg Power in a Representative Cohort of British Men and Women: Associations With Physical Activity, Health Status, and Socioeconomic Conditions

¹ Medical Research Council National Survey of Health and Development, Department of Epidemiology and Public Health, Royal Free and University College Medical School, London, United Kingdom.
² School of Biomedical Sciences, Nottingham University Medical School, United Kingdom.

Address correspondence to Professor D. Kuh, MRC National Survey of Health and Development, Department of Epidemiology and Public Health, Royal Free and University College Medical School, 1-19 Torrington Place, London, United Kingdom, WC1E 6BT. E-mail: d.kuh{at}nshd.mrc.ac.uk

	Abstract

Top Abstract Methods Results Discussion References

 
Background. Understanding the health, behavioral, and social factors that influence physical performance in midlife may provide clues to the origins of frailty in old age and the future health of elderly populations. The authors evaluated muscle strength, postural control, and chair rise performance in a large representative prospective cohort of 53-year-old British men and women in relation to functional limitations, body size, health and activity, and socioeconomic conditions.

Methods. Nurses interviewed 2984 men and women in their own homes in England, Scotland, and Wales and conducted physical examinations in 2956 of them. Objective measures were height, weight, and three physical performance tests: handgrip strength, one-legged standing balance time, and time to complete 10 chair rises. Functional limitations (difficulties walking, stair climbing, gripping, and falls), health status, physical activity, and social class were obtained using a structured questionnaire.

Results. Those with the worst scores on the physical performance tests had higher rates of functional limitations for both upper and lower limbs. Women had much weaker handgrip strength, somewhat poorer balance time, and only slightly poorer chair rise time compared with men. In women, health problems and low levels of physical activity contributed to poor physical performance on all three measures. In men, physical activity was the predominant influence. Heavier weight and poorer socioeconomic conditions contributed to poorer balance and chair rise times.

Conclusions. In this representative middle-aged group, physical performance levels varied widely, and women were seriously disadvantaged compared with men. In general, physical performance was worse for men and women living in poorer socioeconomic conditions with greater body weight, poorer health status, and inactive lifestyles. These findings support recommendations for controlling excess body weight, effective health interventions, and the maintenance of active lifestyles during aging.

Therefore, we evaluated three measures of physical performance in a large prospective British cohort of men and women aged 53 years in relation to functional limitations, body size, health status, physical activity, and socioeconomic conditions. The physical performance assessment included handgrip, a measure of muscle strength (6), a lack of which has significant predictive associations with morbidity, functional independence, and mortality in older populations even after 25 years or more of follow-up (7–9). It also included one-legged standing balance time (postural control) and time taken to rise from a chair (functional leg power), both widely used measures of physical performance that are considered necessary for successful aging and protection from later disability (10).

These three measures provide functionally relevant assessments of physical performance in a large nationally representative cohort of men and women in middle age, along with a profile of potentially remediable factors likely to be associated with them. Understanding the health, behavioral, and social factors that influence such midlife performance may provide clues to the origins of frailty and disability in old age and the health of future elderly populations.

	METHODS

Top Abstract Methods Results Discussion References

 
The Medical Research Council National Survey of Health and Development is a socially stratified sample of all the births in England, Scotland, and Wales that occurred in 1 week in March 1946 and followed regularly ever since (11). Of 2815 men and 2547 women in the original cohort, 3035 (56.6% of the original cohort sample and 70.4% of those still alive and residing in England, Scotland, or Wales) provided information on their health and life circumstances at age 53 years. The sample remains representative in most respects of the British population (12,13). Of 3035 participants, 2984 had home visits by a team of 82 trained nurses and gave information on functional limitations, and 2956 had valid scores on at least one of the three physical performance tests administered by the nurses. All assessments received ethical approval and all participants gave informed consent.

Physical Measurements
Height.-- The nurses measured participants' height (while they wore no shoes) using a portable stadiometer (CMS, London, UK) to the nearest 0.5 cm. Participants were required to keep their heads in the Frankfort plane, to stand as tall as possible with hands hanging by sides, and to take in a deep breath during the measurement.

Weight.-- The nurses recorded participants' weight (while they wore light clothing but no shoes) to the nearest 0.5 kg using CMS weighing scales.

Handgrip strength.-- The nurses measured voluntary muscle strength isometrically using an electronic handgrip dynamometer (14,15). The dynamometers were calibrated at the start using a back-loading rig; they are accurate, linear, and stable to ±0.5 kg. Each nurse interviewer was taught to give strong verbal encouragement to elicit maximal performance from the participants. The nurses recorded two values for each hand, and the highest was used in the analyses. The intraparticipant retest variability for maximal voluntary tests of strength in those unused to such measurements is approximately ±9% (16).

Standing balance time.-- The nurses assessed standing balance time, using a stopwatch, as the longest time, up to a maximum of 30 seconds, for which the participants could maintain a one-legged stance in a standard position (17,18). With shoes removed, the participants folded their arms and raised the preferred foot a few inches off the ground behind the leg by bending the knee sufficiently. This was assessed first with the participants' eyes open and then with eyes closed. Most participants completed 30 seconds with their eyes open, so scores from the "eyes closed" test only were used to avoid a ceiling effect. High scores indicate good performance.

Chair rise time.-- The nurses assessed chair rise time, using a stopwatch, as the minimum time taken to rise from a sitting position into a standing position with straight back and legs and then sit down again 10 complete times (19). The participants removed their shoes and sat in an armless straight-backed hard chair of normal height with a horizontal flat seat (with the upper surface of the seat positioned approximately 46 cm from the floor). The reciprocal of time taken (multiplied by 100) was used, so that a high score represented a good performance, as with the other two measures (20).

Questionnaire Data
Physical activity (general).-- The nurses asked the participants to number the occasions in the previous 4 weeks in which they had participated in sports, exercises, or other physical activities in their leisure time. The categories were inactive (no occasions), mildly active (one to four occasions), or moderately active (more than four occasions).

Physical activity (specific).-- The nurses assessed participant-reported use of strong hand movements in vigorous activities, such as wringing water out of a towel or carrying heavy bags, on a 5-point scale of frequency from never to several times a day.

Functional limitations.-- The nurses asked participants whether they had difficulty, because of long-term health problems, holding something heavy such as a full kettle or removing a tightly sealed lid from a jar (yes/no), walking for a quarter of a mile (400 yards) on the level (yes/no), or walking up and down a flight of 12 stairs in a normal manner (yes/no). The nurse also recorded how many times the participants had fallen in the last year, and those who had fallen three times or more were distinguished from the rest.

Assessed and reported health.-- Clinical signs of osteoarthritis in the hand were obtained from a detailed examination that nurses were trained to perform using previously validated criteria (21). This involved identification of the presence of Heberden nodes, Bouchard nodes, or squaring at the carpometacarpal joint. Hand osteoarthritis was defined as involvement of at least 1 joint (22). We considered that participants had musculoskeletal symptoms if they reported that in the last 12 months they had suffered either pain or stiffness in either knee or either hand on most days for at least 1 month, or sciatica, lumbago, or severe backache. We used the U.K. Medical Research Council's standardized questions to assess respiratory symptoms (23). We identified a group with the most severe respiratory symptoms by reports of one or more of the following: a wheezy or whistling chest most days or nights; usually bringing up phlegm or coughing in the morning or during the day or night in winter for at least 3 months each year; or more than one chest illness in the last 3 years that kept them off work or indoors for 1 week or more. A group with other common health conditions that might be disabling or life threatening was also identified. These conditions were diabetes (n = 79), cancer (n = 95), or epilepsy (n = 47) in the last 10 years; or cardiovascular disease (n = 177) involving one or more of the following: a heart attack (n = 48) or stroke (n = 25) ever, aortic stenosis or valvular disease in the last 10 years (n = 6), physician-diagnosed angina or Rose angina grade I or II elicited by standardized questions (24) (n = 142), or intermittent claudication (n = 12) also elicited by standardized questions (24).

Socioeconomic conditions.-- Adult social class, based on the British Registrar General's social class classification derived from the current or last occupation of the participant, was used to assess socioeconomic conditions. Participants were separated into nonmanual or manual labor social classes.

Statistical Analyses
We analyzed men and women separately throughout, but used tests for interactions between sex and other risk factors to compare sex differences formally. Because balance time had a positively skewed distribution, we normalized it using a natural logarithm transformation. To explore the relations between physical performance and functional limitations, we divided the values for grip strength, balance, and chair rise time into thirds and compared the prevalence of functional limitations across these thirds using chi-square tests for trend. We used chi-square tests to compare the prevalence of functional limitations in those unable or unwilling to do the tests with all those who had taken the tests. We conducted further analyses using ordinary least squares regression. Using the continuous data and multiple regression models, we assessed the relationships of handgrip strength, balance, and chair rise time with adult height, weight, and their interaction. Height and weight were centered on the mean. Then we evaluated the relationships of handgrip strength, balance, and chair rise time with current activity levels and assessed and reported health and social class. In these models, we entered each of the independent variables, adjusting only for height and weight (as established in the previous analyses), and then we included all of the variables simultaneously in fully adjusted models. Mean values for handgrip strength, balance, and chair rise time are given after weighting to allow for the initial sampling procedure (13). We present the results for all other analyses with the unweighted sample because they were essentially no different from the results of the weighted analyses.

	RESULTS

Top Abstract Methods Results Discussion References

 
Table 1 lists the characteristics of the sample. We obtained valid measurements for handgrip strength for 1406 men and 1444 women, or 96.4% of those interviewed. The responses were 94.2% for balance time and 93.3% for chair rise time. The small shortfall occurred either because participants could not attempt or complete the tests or because they were unwilling to take the tests or their scores were invalid. Grip strength was less than 20 kg in 16% of women and 2% of men. The mean time taken to perform 10 chair rises was 19.3 seconds (harmonic mean, equivalent to the reciprocal of 5.19 [x100]), and 1 in 10 participants took 30 seconds or more to complete them. One half of the sample could not maintain one-legged standing balance for 5 seconds with their eyes closed.

Women had significantly poorer chair rise times compared with men (by 6%), although this difference was much less than for handgrip strength or balance time (Table 1). We noted an interaction between height and weight for men (p =.03) (Table 3) such that performance declined much more strongly with height among heavier than lighter men. Similar models to those used for balance time confirmed that the relationships between chair rise time and height and weight were significantly greater for women than for men.

Physical Performance and Physical Activity
More than one half the participants reported "never" using strong hand movements in vigorous activities (Table 1). Handgrip strength was strongly and linearly related to reported use. Frequency of strong hand movements was entered into the regression models as a continuous variable denoting increasing use, controlling for height (in men and women) and weight (in men only) (Table 4, model 1). Only approximately one half of the participants were physically active in their leisure time (Table 1). Moderately and mildly active men had stronger handgrip strength compared with inactive men (Table 4, model 1). We found no such relation in women.

Socioeconomic Conditions
We noted no social class differences with respect to handgrip strength (Table 4, model 1), but men and women from the manual social classes had significantly poorer balance and chair rise times compared with those from the nonmanual labor classes (Tables 5 and 6, model 1). The reduction in balance time was 28% for men and 22% for women.

In fully adjusted models, we observed a better balance time in men and women who were mildly or moderately active, and a poorer balance time remained for those from the manual social classes (Table 5, model 2). Generally, associations between balance time and the ill-health indicators were attenuated in the fully adjusted model and remained significant only for musculoskeletal symptoms in women and disabling and life-threatening conditions in men. After simultaneous adjustment, chair rise time remained related to all the factors considered, except for social class in men (Table 6, model 2).

Characteristics of Those Unable To Complete the Tests
In addition to their greater prevalence of functional limitations, men and women who could not take the physical performance tests, particularly the one-legged balance stand and the chair rises, experienced more poor health compared with those who took the tests. They were also more likely to be inactive and to come from the manual social classes.

	DISCUSSION

Top Abstract Methods Results Discussion References

 
This report provides normal mean values for handgrip strength and two measures of physical performance that are representative of middle-aged British men and women. In general, men and women with better physical performance had fewer functional limitations and were more likely to be physically active, in better health, of lighter weight, and to belong to the nonmanual social classes. Our finding that one half of this representative sample could not maintain the one-legged standing balance for 5 seconds with their eyes closed suggests that poor balance under dark conditions is common in a middle-aged population. The mean time taken to perform 10 chair rises was slightly greater than predicted at age 55 years from a small study of healthy men and women (19). Levels of physical activity were alarmingly low for a population still in middle age, although this finding is consistent with the results of other surveys (26).

We expected to find the strong associations between poor physical performance and higher rates of functional limitations of both upper and lower limbs. The only exception to this pattern were reported falls, and this may be a result of our inability to separate injurious from noninjurious falls, because the latter may be a marker of an active lifestyle in this age group. Functional limitations were prevalent in those in the bottom one third of the performance tests, particularly in women, and may noticeably restrict daily activities.

We found sex differences in the three performance measures. Women are known to have poorer muscle strength than men, especially in the upper body, and the 40% deficit in absolute handgrip strength was similar to that found in other surveys (14,26,27). For the dynamic weight-bearing performances, which are more relevant for maintaining an independent lifestyle, the difference is less marked but still significant (19,28). Women are disadvantaged when facing physical tasks, and this was reflected in the much higher proportion of women reporting functional limitations.

Within the general pattern, we found marked differences in the relations of the three performance measures with weight, health, activity, and social class. Handgrip strength was influenced by few of these factors, and chair rising was affected by most of them. This is not surprising. Handgrip is a simple isometric test of upper body muscle strength, whereas the dynamic measures use leg muscles and require neuromuscular speed and control, with chair rising being arguably the most complex. Therefore, they should not be used as surrogates for each other in assessments of physical performance.

The strong association between handgrip strength and reported strong hand movements, as well as the additional association in men with physical activity (despite the nonspecific weight-bearing nature of most of the activities reported), have also been found in older men and women (14). For the dynamic measures, the effects of physical activity in leisure time were consistently positive and significant for women and men. This confirms the importance of active lifestyles for maintaining physical performance.

Similarly, the negative effects of poor health were particularly strong for the dynamic performance measures and remained after controlling for the positive effects of physical activity. A study of older men and women found that postural balance was related to physical activity but failed to show an effect of health status (29). Few diseases impinge directly on muscle strength, but many have subtle deleterious effects on central coordination and control of postural and dynamic movement. Poor health or the discomforts associated with it are assumed to have indirect effects through decreased levels of physical activity, and we found some evidence of this in the fully adjusted models, which showed in all cases that the effects of health and physical activity were mutually attenuated.

Socioeconomic status has been shown in this cohort and in other studies to be associated with health problems (30) and with differing patterns of physical activity (31). Nevertheless, its effects remained significant for balance and chair rise time even after adjustment for height, weight, activity, and health status. Social class evidently represents additional factors to which these complex measures are more sensitive than simple muscle strength.

Heavier men and women had poorer balance times compared with lighter men and women, and this is likely to be due to their greater body fat (32). They also had poorer chair rise times, probably because a heavier person has more mass to lift. The proportion of lean to fat mass is important for these weight-bearing activities and underlines the need to control excess body fat in middle age. In contrast, heavier men had better handgrip strength than did lighter men, which is likely to be due to the contribution of lean mass. The lack of a similar association in women in this study and elsewhere (14) may be attributed to their greater proportion of body fat (27).

We also found sex differences in the relations of handgrip strength with health and activity. Physical activity in leisure time had a stronger protective effect on handgrip strength in men than in women. In contrast, health problems generally had more effect on handgrip strength in women than in men. This sex difference in outcome is similar to that found in a large survey of older British men and women (14). For women, some aspects of health and physical activity remained significant for all performance measures even after adjustment for all the other factors. These results suggest that, despite women's greater longevity, their poor health is an important cause of weakness and incapacity well before they reach old age. For men, physical activity predominated and their performance measures appeared to be relatively immune to poor health, despite the reported predictive power of handgrip strength for long-term morbidity and death in older men.

In this middle-aged sample, 2% to 5% could not complete each of the assessments. These persons had more functional limitations, were less active, suffered more from poor health, and were more likely to come from the manual labor social class. The exclusion of this more disadvantaged group may have caused the strength of the observed associations to underestimate the true associations in the general population.

Conclusion
Physical performance levels varied widely, and the prevalence of functional limitations, poor health, and inactivity were high in this representative middle-aged group. Women were seriously disadvantaged compared with men. In general, physical performance was worse for men and women with greater body weight, poorer health status, inactive lifestyles, and living in poorer socioeconomic conditions. Our findings support recommendations for controlling excess body weight, effective health interventions, and the maintenance of active lifestyles during aging.

	Acknowledgments

 
Supported by the Medical Research Council, United Kingdom.

The study team also includes Cyrus Cooper, Avan Aihie Sayer, and Jason Poole of the Medical Research Council Environmental Epidemiology Unit, Southampton University, Southampton, United Kingdom.

	Footnotes

 
Decision Editor: John E. Morley, MB, BCh

Received June 13, 2003

Accepted October 3, 2003

	References

Top Abstract Methods Results Discussion References

 

1. National Research Council. Preparing for an Aging World: the Case for Cross-National Research. Washington, DC: National Academy Press; 2001.
2. Mathers CD, Robine JM. International trends in health expectancies: a review. Austral J Aging. 1998;17:(Suppl): 51-55.
3. Freedman VA, Martin LG. Understanding trends in functional limitations among older Americans. Am J Public Health. 1998;88:1457-1462.[Abstract/Free Full Text]
4. Melzer D, McWilliams B, Brayne C, et al. Socioeconomic status and the expectation of disability in old age: estimates for England. J Epidemiol Community Health. 2000;54:286-292.[Abstract/Free Full Text]
5. Grundy E, Ahlburg D, Ali M, et al. Disability in Great Britain. Department of Social Security Report no. 94. London: HMSO, 1999.
6. Tornvall G. Assessment of physical capabilities with special reference to the evaluation of maximal voluntary isometric muscle strength and maximal working capacity. Acta Physiol Scand. 1963;58:(Suppl): 201.[Medline]
7. Metter EJ, Talbot LA, Schrager M, et al. Skeletal muscle strength as a predictor of all-cause mortality in healthy men. J Gerontol Biol Sci Med Sci. 2002;57A:B359-B365.
8. Rantanen T, Guralnik JM, Foley D, et al. Midlife hand grip strength as a predictor of old age disability. JAMA. 1999;281:558-560.[Abstract/Free Full Text]
9. Rantanen T, Harris T, Leveille SG, et al. Muscle strength and body mass index as long-term predictors of mortality in initially healthy men. J Gerontol Biol Sci Med Sci. 2000;55A:M168-M173.
10. Guralnik JM, Ferrucci L, Pieper CF, et al. Lower extremity function and subsequent disability: consistency across studies, predictive models, and value of gait speed alone compared with the short physical performance battery. J Gerontol Biol Sci Med Sci. 2000;55A:M221-M231.
11. Wadsworth MEJ, Kuh DJL. Childhood influences on adult health: a review of recent work in the British 1946 national birth cohort study, the MRC National Survey of Health and Development. Paediatr Perinat Epidemiol. 1997;11:2-20.[Medline]
12. Wadsworth MEJ, Mann SL, Rodgers B, Kuh DL, Hilder WS, Yusuf EF. Loss and representativeness in a 43 year follow-up of a national birth cohort. J Epidemiol Community Health. 1992;46:300-304.[Abstract/Free Full Text]
13. Wadsworth ME, Butterworth SB, Hardy RJ, et al. The life course prospective design: an example of benefits and problems associated with study longevity. Soc Sci Med. 2003;57:2193-2205.
14. Bassey EJ, Harries UJ. Normal values for handgrip strength in 920 men and women aged over 65 years, and longitudinal changes over 4 years in 620 survivors. Clin Sci. 1993;84:331-337.[Medline]
15. Kuh D, Bassey EJ, Hardy R, Aihie Sayer A, Wadsworth M, Cooper C. Birthweight, childhood size and muscle strength in adult life: evidence from a birth cohort study. Am J Epidemiol. 2002;156:627-633.[Abstract/Free Full Text]
16. Bassey EJ. Longitudinal changes in selected physical capabilities: muscle strength, flexibility and body size. Age Ageing. 1998;27:12-16.
17. Rikli R, Busch S. Motor performance of women as a function of age and physical activity. J Gerontol Biol Sci Med Sci. 1986;41A:645-649.
18. Kronhed G, Moller C, Olsson B, et al. The effect of short-term balance training on community-dwelling older adults. J Aging Phys Activity. 2001;9:19-31.
19. Csuka M, McCarty DJ. Simple method for measurement of lower extremity muscle strength. Am J Med. 1985;78:77-81.
20. Skelton DA, Greig CA, Davies JM, Young A. Strength, power and related functional ability of healthy people aged 65-89 years. Age Ageing. 1994;23:371-377.[Abstract/Free Full Text]
21. Hart D, Spector T, Egger P, Coggon D, Cooper C. Defining osteoarthritis of the hand for epidemiological studies: the Chingford study. Ann Rheum Dis. 1994;53:220-223.[Abstract/Free Full Text]
22. Sayer AA, Poole J, Cox V, Kuh D, Hardy R, Wadsworth M, Cooper C. Weight from birth to 53 years: a longitudinal study of the influence on hand osteoarthritis. Arthritis Rheum. 2003;48:1030-1033.[Medline]
23. Medical Research Council. Questionnaire on Respiratory Symptoms and Instructions for Interviewers. London: Medical Research Council, 1976.
24. Rose G, Blackburn H, Gillum R, et al. Cardiovascular Survey Methods. Geneva: World Health Organization, 1982.
25. Cole TJ. Sympercents: symmetric percentage differences on the 100 log_e scale simplify the presentation of log transformed data. Stat Med. 2000;19:3109-3125.[Medline]
26. Allied Dunbar National Fitness Survey. Main Findings: A Report on Activity Patterns and Fitness Levels 1992. London: Sports Council & Health Education Authority: 1992.
27. Sternfield B, Ngo L, Satariano WA, Tager IB. Association of body composition with physical performance and self-reported functional limitation in elderly men and women. Am J Epidemiol. 2002;156:110-121.[Abstract/Free Full Text]
28. Guralnik JM, Ferrucci L, Simonsick EM, Salive ME, Wallace RB. Lower extremity function in persons over the age of 70 years as a predictor of subsequent disability. N Engl J Med. 1995;332:556-561.[Abstract/Free Full Text]
29. Era P, Avlund K, Jokela J, et al. Postural balance and self-reported functional ability in 75 year old men and women: a cross-national comparative study. J Am Geriatr Soc. 1997;45:21-29.[Medline]
30. Kuh DJL, Wadsworth MEJ. Physical health status at 36 years in a British national birth cohort. Soc Sci Med. 1993;37:905-916.
31. Kuh DJL, Cooper C. Physical activity at 36 years: patterns and childhood predictors in a longitudinal study. J Epidemiol Community Health. 1992;46:114-119.[Abstract/Free Full Text]
32. Winters KM, Snow CM. Body composition predicts bone mineral density and balance in premenopausal women. J Women's Health Gend Based Med. 2000;9:865-872.[Medline]

This article has been cited by other articles:

				I. Colman, J. Murray, R. A Abbott, B. Maughan, D. Kuh, T. J Croudace, and P. B Jones Outcomes of conduct problems in adolescence: 40 year follow-up of national cohort BMJ, January 13, 2009; 338(jan08_2): a2981 - a2981. [Abstract] [Full Text] [PDF]

				D. Kuh, R. Cooper, R. Hardy, J. Guralnik, M. Richards, and the Musculoskeletal Study Team Lifetime Cognitive Performance is Associated With Midlife Physical Performance in a Prospective National Birth Cohort Study Psychosom Med, January 1, 2009; 71(1): 38 - 48. [Abstract] [Full Text] [PDF]

				B. E. Alvarado, M.-V. Zunzunegui, F. Beland, and J.-M. Bamvita Life Course Social and Health Conditions Linked to Frailty in Latin American Older Men and Women J. Gerontol. A Biol. Sci. Med. Sci., December 1, 2008; 63(12): 1399 - 1406. [Abstract] [Full Text] [PDF]

				H. J. Martin, H. E. Syddall, E. M. Dennison, C. Cooper, and A. A. Sayer Relationship between customary physical activity, muscle strength and physical performance in older men and women: findings from the Hertfordshire Cohort Study Age Ageing, September 1, 2008; 37(5): 589 - 593. [Full Text] [PDF]

				D. Kuh and the New Dynamics of Ageing (NDA) Preparatory Netwo A Life Course Approach to Healthy Aging, Frailty, and Capability J. Gerontol. A Biol. Sci. Med. Sci., July 1, 2007; 62(7): 717 - 721. [Full Text] [PDF]

				D. M. Kado, M.-H. Huang, C. B. Nguyen, E. Barrett-Connor, and G. A. Greendale Hyperkyphotic Posture and Risk of Injurious Falls in Older Persons: The Rancho Bernardo Study J. Gerontol. A Biol. Sci. Med. Sci., June 1, 2007; 62(6): 652 - 657. [Abstract] [Full Text] [PDF]

				K. Y. Z. Forrest, J. M. Zmuda, and J. A. Cauley Correlates of Decline in Lower Extremity Performance in Older Women: A 10-Year Follow-Up Study J. Gerontol. A Biol. Sci. Med. Sci., November 1, 2006; 61(11): 1194 - 1200. [Abstract] [Full Text] [PDF]

				Y.-H. Pua Allometric Analysis of Physical Performance Measures in Older Adults Physical Therapy, September 1, 2006; 86(9): 1263 - 1270. [Abstract] [Full Text] [PDF]

				D. Kuh, R. Hardy, S. Butterworth, L. Okell, M. Richards, M. Wadsworth, C. Cooper, and A. A. Sayer Developmental Origins of Midlife Physical Performance: Evidence from a British Birth Cohort Am. J. Epidemiol., July 15, 2006; 164(2): 110 - 121. [Abstract] [Full Text] [PDF]

				J. M. Guralnik, S. Butterworth, M. E. J. Wadsworth, and D. Kuh Childhood socioeconomic status predicts physical functioning a half century later. J. Gerontol. A Biol. Sci. Med. Sci., July 1, 2006; 61(7): 694 - 701. [Abstract] [Full Text] [PDF]

				D. Kuh, R. Hardy, S. Butterworth, L. Okell, M. Wadsworth, C. Cooper, and A. Aihie Sayer Developmental origins of midlife grip strength: findings from a birth cohort study. J. Gerontol. A Biol. Sci. Med. Sci., July 1, 2006; 61(7): 702 - 706. [Abstract] [Full Text] [PDF]

This Article Abstract Full Text (PDF) Services Download to citation manager Citing Articles Citing Articles via HighWire PubMed PubMed Citation