Physical test performance

In this study, men performed b e tte r than w om en in the physical tests but not in the object recall test. Similar sex differences in physical performance were seen in other studies (Bassey et al, 1989a; Hyatt et al, 1990; Bassey & Harries, 1993; W atters et al, 1985; Liang & Chumlea, 1998). B e tte r physical performance by men is common at all ages, but in older populations it may partly be ascribed to a higher occurrence o f health problems in women, which may have reduced the level o f customary physical activity. P oor health and reduced physical activity m ay also independently affect physical performance.

Handgrip strength is one o f th e most com mon physical tests and has been directly related to nutritional status. Refugee m en had a mean value o f 30.3 kg and women o f 22.3 kg. The sex difference was not entirely explained by skeletal size; women had significantly lower strength per kg body weight (P<0.001). H ow ever the difference may not be present when strength is expressed per kg muscle mass as shown by Frontera et al, 1991). Grip strength values o f only few developing country populations are available. Table 8.3 shows values o f R w andan refugees and people from urban India and rural Thailand and Malawi. V alues in the Indian population are much lower than in the other three populations, which d o not differ much from each other. It is possible that the differences between the A frican and the urban Indian population also reflect different lifestyles and occupational histories. The rural people were used to heavy agricultural work whereas the Indian slum dwellers had a variety o f occupational backgrounds such as cotton mill worker, road cleaner o r menial office w orker (HAI & LSHTM , 1997). Varakamin et al (1998) also suggested that lifestyle may influence both body composition as well as m uscular strength. This was based on a comparison between rural active elderly (data in table 8.3) and sedentary elderly living in a residential home in

Thailand. The institutionalised, who had access to better food and care, had higher body fat and lower handgrip strength. T he three groups o f rural elderly have very similar handgrip strengths.

The refugees’ grip strength values were either below those o f developed country populations o r similar, particularly in women. As it is unlikely that elderly in developed countries w ere more active, this may be due to a poorer nutritional status o f the refugees o r may reflect the earlier onset o f old age in developing countries. Based on an U K sample, W ebb et al (1989) proposed lower limits o f acceptable pre-operative grip strength for age and sex, based o n the best combination o f sensitivity and specificity. Grip strength values o f the Rwandan refugees were at all ages below the suggested limits and men w ere 10-20% m ore below ‘standard’ than women. This w ould suggest that refugee wom en not only had a high arm muscle mass but also high grip strength compared to other women.

The prevalence o f impaired handgrip (using the 25-percentile cu t-o ff from the to ta l sample) am ong kyphotic people w as much higher than am ong non-kyphotic people. F or women this was not entirely explained by the higher mean age in the kyphotic gro u p , as the prevalence o f functional impairment in the oldest non-kyphotic group (¿7 0 years) was lower.

Table 8.3 Mean handgrip strength in developing and developed country populations

C h a p te r 8 D isc u ssio n 179

Country n Sex Age (yrs) Handgrip (kg) SD Reference

Rwanda 828 m 50-92 30.3 6.7 present

rural refugees 50-59 32.9 6.6 study

60-69 29.0 5.7 £70 26.2 6.0 f 50-92 22.3 5.1 50-59 23.9 5.0 60-69 21.6 4.6 £70 19.0 4.3 Malawi 284 m 55-94 28.0 5.9 Chilima (1998) rural 55-59 32.3 5.5 60-69 29.0 6.1 £70 25.9 5.2 f 55-94 21.7 4.5 55-59 22.9 4.0 60-69 21.7 4.9 £70 19.7 3.2 Thailand 244- m 60-69 31.4 7.8 Varakamin et al rural 280 70-79 25.0 6.3 (1998) f 60-69 22.6 4.7 70-79 19.7 4.5 India 1097 m 50-96 22.9 6.5 Manandhar (1999) urban 50-64 23.7 6.5 £65 20.8 6.5 f 50-96 13.4 4.5 50-64 14.0 4.4 £65 11.1 4.2 UK 350 m >65 37.2 8.1 Bassey (1998) community-living f >65 21.6 5.9

UK 405 m £65 36.6 Lehman & Bassey

community-living f £65 21.3 (1996)

UK 920 m >65 33.8 9.3 Bassey & Harries

community-living f >65 19.5 6.3 (1993) UK 100 m 65-69 46.7 8.0 Skelton et al healthy volunteers 70-74 40.2 5.0 (1994) 75-79 37.1 5.0 r 65-69 26.0 3.0 70-74 27.0 5.0 75-79 22.0 6.0 UK 92 m 65-89 32.7 10.1 Hyatt etal (1990)

ambulant, attending day care/day hospital

f 65-89 22.0 8.6

Yugoslavia 100 65-80 48.1 3.4 Suboticanec et al

Repeated chair stands m easure both lower extremity muscle strength and endurance. In the Rwandan sample 12.4% o f the men and 15.7% o f the women were unable to rise five times from a chair. In a highly functioning American cohort aged 70 to 79 years, 51% completed this task in 12 seconds or less (Seeman et al, 1994). O f the Rwandan people (who were younger), only 36.8% managed within this time. However they performed better than another gro u p o f American community living people over 70 years: 14.8% o f the men and 27.4% o f th e women did not complete five rises (Merrill et al, 1997). Elderly Europeans participating in the SENECA study (1996b) took a similar time as the refugees to complete five chair stands, but the Europeans were older (74-79 years). In older Chinese people living at home, men and younger people perform ed better in repeated chair stands than women and older people, and those engaged in regular exercise did better than th e physically inactive (Liang & Chumlea, 1997). Differences in performance between populations may also be due to differences in prevalence o f obesity that may be an impediment to chair rises and other tests.

A high BMI was found to be associated also with low shoulder range in women (Bassey, 1989b). It was assumed that fatty tissue may restrict range, particularly when muscle strength is low. Shoulder flexibility is relevant to self-care tasks such as bathing, dressing and grooming and certain household tasks e.g. carrying loads on the head. Shoulder rotations were unimpaired in 79.1% o f the Rwandan men and 76.5% o f the women. This compares to 84.2% fo r American men and 71.2% for women (Merrill et al, 1997). O f Sri Lankan elders. 69% managed an external shoulder rotation (Fernando & Seneviratna, 1993).

The present study show ed poorer performance in all tests in each older age group with a more marked decrease above age 70. This is not only in agreement with cross-sectional studies in India and Malawi (Chilima, 1998; Manandhar, 1999), but also with longitudinal studies th a t found a significant decline with age in functional performance, even at an accelerating rate at more advanced age (Kallman et al, 1990; Grimby, 1995). Psychomotor speed, m uscle strength and mobility were found to be predictive o f survival especially in women (E ra & Rantanen, 1997).

Cross-sectional studies tend to underestimate true age-related strength losses due to selective survivorship (Hurley, 1995). A large longitudinal study among o ld e r non- institutionalised Americans dem onstrated a greater decline in physical function with age than suggested by cross-sectional studies. The rate o f decline was higher at more advanced age and higher in w om en (Beckett et al, 1996). Bassey & Harries (1993) also found greater loss o f handgrip strength over four years (3% per year for m en, 5% per year for women) than predicted from baseline data.