Assessing Muscle Function and Balance Problems at Home, in the Clinic, and in Research 25 th IOA Colloquium on Aging September 17, 2013

Transcription

1 Assessing Muscle Function and Balance Problems at Home, in the Clinic, and in Research 25 th IOA Colloquium on Aging September 17, 2013 Bjoern Buehring, M.D. University of Wisconsin School of Medicine and Public Health GRECC, William S. Middleton Memorial Veterans Hospital Madison, WI, USA s i t v e r i n U. M y of W AO i s co n s A O I. i n a di s o n

2 Disclosures/Conflicts of Interest None

3 Outline How independent and active are older Americans? Muscle and Biomechanics 101 How do you know how well your muscles work? The impact of poor muscle function on health

4 Activities of Daily Living are Parameters of Independence and Mobility Activity of Daily Living Personal hygiene and grooming Bowel and bladder management Self feeding Dressing and undressing Functional transfers (getting into and out of bed or wheelchair, getting onto or off toilet, etc.) Ambulation (walking with or without use of an assistive device) Instrumental Activities of Daily Living Taking medications as prescribed Managing money Use of telephone or other technology Housework Shopping for groceries or clothing Transportation within the community

5 Impaired Function is Common in Older Adults Several governmental and non-governmental agencies collect survey and health data on older adults The Older Americans 2012: Key Indicators of Well-Being report by the Federal Interagency Forum on Aging-Related Statistics (Forum) summarizes several of these indicators Data presented here are based on: Centers for Medicare and Medicaid Services Medicare Current Beneficiary Survey Centers for Disease Control and Prevention National Center for Health Statistics National Health Interview Survey _Documents/Docs/EntireChartbook.pdf#page=140

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7 Impaired Function is Common in Older Adults Table 20a. Percentage of Medicare enrollees age 65 and over who have limitations in activities of daily living (ADLs) or instrumental activities of daily living (IADLs), or who are in a long-term care facility, selected years Total IADLs only 1 2 ADLs ADLs ADLs Long-term care facility Table 20b. Percentage of Medicare enrollees age 65 and over who have limitations in activities of daily living (ADLs) or instrumental activities of daily living (IADLs), or who are in a long-term care facility, by sex, 2009 Both Sexes Men Women Total IADLs only ADLs ADLs ADLs Long-term care facility _Documents/Docs/EntireChartbook.pdf#page=140

8 Impaired Function is Common in Older Adults Table 20c. Percentage of Medicare enrollees age 65 and over who are unable to perform certain physical functions, by sex, 1991 and 2009 Function Men Stoop/kneel Reach over head Write/grasp small objects Walk 2 3 blocks Lift 10 lbs Women Stoop/kneel Reach over head Write/grasp small objects Walk 2 3 blocks Lift 10 lbs _Documents/Docs/EntireChartbook.pdf#page=140

9 Impaired Function is Common in Older Adults functions, by selected characteristics 2009 Selected characteristic Men Women Age and over Race White, not Hispanic or Latino Black, not Hispanic or Latino Hispanic or Latino (any race) _Documents/Docs/EntireChartbook.pdf#page=140

10 Watching TV is THE Leisure Activity of Older Adults Table 28b. Average number of hours and percentage of total leisure time that people age 55 and over spent doing selected leisure activities on an average day, by age group, and over Average Average Average hours Percent of hours Percent of hours Percent of Selected leisure activities per day leisure time per day leisure time per day leisure time Socializing and communicating Watching TV Participation in sports, exercise, and recreation Relaxing and thinking Reading Other leisure activities NOTE: Other leisure activities includes activities such as playing games, using the computer for leisure, arts and crafts as a hobby, arts and entertainment (other than sports), _Documents/Docs/EntireChartbook.pdf#page=140

11 Aerobic and Strength Training is Uncommon in Older Adults Table 24a. Percentage of people age 45 and over who reported participating in leisure-time aerobic and musclestrengthening activities that meet the 2008 Federal physical activity guidelines, by age group, Year and over and over NOTE: This measure of physical activity differs from previous editions of Older Americans _Documents/Docs/EntireChartbook.pdf#page=140

12 Aerobic and Strength Training is Uncommon in Older Adults Table 24b. Percentage of people age 65 and over who reported participating in leisure-time aerobic and musclestrengthening activities that meet the 2008 Federal physical activity guidelines, by sex and race and ethnicity, 2010 Aerobic activity only All White, not Hispanic or Latino Black, not Hispanic or Latino Hispanic or Latino Both sexes Men Women _Documents/Docs/EntireChartbook.pdf#page=140

13 Muscle 101 The musculoskeletal system is needed for locomotion and posture It consists of several tissues including bone, muscle, joints, ligaments and tendons Muscle is attached to bone through tendons Muscle contractions lead to body movement

14 Muscle 101 Muscle cells (or fibers) are long and are grouped into fascicles Several fascicles make up a muscle Muscle cells contain proteins that move within the cell and shorten their length The nervous system is responsible for initiating, controlling and coordinating contractions

15 Biomechanics 101 There are different types of muscle contractions Concentric = muscle shortens as it contracts Eccentric = muscle lengthens as it contracts Isometric = muscle remains at the same length

16 Biomechanics 101 Force (F, Newton) = Mass (m, kilogram) x Acceleration (a, meters/second 2 ) Velocity (v, meters/second) = Distance (d, meters) / Time (t, seconds) Power (P, Watts) = Force (F, Newton) x Velocity (v, meters/second) = Work (W, Joule) / Time (t, seconds) Sway can be measured in Path length (Length, meters) or Area of Sway (Area, meter 2 )

17 Grip Strength Can you open a jar? Power grip (232.8 N), Precision grip (248.6 N) Kuo, Proc Inst Mech Eng H,

18 Grip Strength Grip strength is measured with a dynamometer It is an isometric contraction It measures maximal force

19 Leg Power Can you get up from a chair? out of bed? out of a car?

20 Leg Power Leg power can be measured with the repeated chair rise test the get up and go test Power assesses muscle force and speed (velocity)

21 Leg Power Repeated chair rises can be measured with a stop watch or force platform

22 Gait speed How long does it take you to cross the street? Distance: 28 meters (91.9 feet) Time the light is green: 20 seconds (plus 10 seconds of flashing) Although walking requires muscle power it is largely dependent on velocity (not force)

23 Gait speed How long does it take you to cross the street? If gait speed is: 1.3 m/s à 21.5 seconds 1.0 m/s à 28 seconds 0.8 m/s à 35 seconds 0.5 m/s à 56 seconds

24 Gait speed

25 Balance / Sway Do you have difficulties getting out of a bathtub?

26 Balance / Sway Balance and Sway can be measured with The Romberg stance test The semi-tandem and tandem stance test The functional reach test On a force platform

27 Balance / Sway The Romberg and Tandem Stance tests These tests examine static balance

28 Balance / Sway The functional reach test This test examines dynamic balance Individuals are asked to lean forward as far as they can without taking a step forward Pérennou, 2005

29 Balance / Sway Sway can be quantified with a force platform

30 How Do you Measure Muscle Mass and Function? Muscle mass is often measured by dual energy x-ray absorptiometry (DXA) info.blockimaging.com

31 Measuring Muscle and Fat with DXA Individuals with the same body mass index can have different body composition Older individuals have more fat mass and lower muscle mass

32 Cut-off values for muscle function tests Muscle function test Grip strength (dynamometer) Chair rise (5 chair rises) Get up and go (get up from chair walk 10 feet, turn around, walk back and sit down) Walking speed (20 feet) Romberg, (semi-) tandem stance Functional reach (leaning forward) Muscle mass (DXA appendicular lean mass, arms + legs) Cut-off Females: <20kg; Males: <30kg > seconds (depending on age and gender) Females and Males > 12 seconds Females and males < m/s Able to stand for 60 (or 30) seconds < 6-7 inches Females: <5.45 kg/m 2 Males < 7.45 kg/m 2

33 Grip Strength is Associated with ADLs / IADLs to 68- year-old healthy men had grip strength measured 1965 through surviving participants had disability assessment 25 years later Rantanen, JAMA, 1999, 10;281(6):558-60

34 Impaired Physical Performance Increases Hip Fracture Risk Data from the MrOS study, which included 5995 men age 65+ Adapted from Cawthon, et. al., J Bone Miner Res, 2008, 23:

35 Slow Walking Speed is Associated with Increased Mortality Relationship of walking speed and mortality InChianti Study (Aging in the Chianti area study), started 1998, ~1,150 participants, between ages 65 and 102 Cesari, J Gerontol A Biol Sci Med Sci, 2009, 64:377-84

36 Summary Impaired physical function is common in older adults The (Neuro-) Musculoskeletal system consists of many tissues including bones, muscles, joints and the nervous system Muscle contractions are the origin of movement Muscle functions include force, power, speed and balance Poor muscle function is associated with decreased physical function, hospitalizations and death

37 Thank You