journal review

1. Effects of three different low-
intensity exercise interventions
on physical performance,
muscle CSA and activities of
daily living: A randomized
controlled trial
Presented by : Merie Octavia
Supervisor : dr. Melinda Harini, SpKFR-K

3. Introduction
+ Proportion older adults  rapidly growing
+ US residents aged ≥ 65  projected to double in the next 30 years  20%
of population
+ Elderly  the least physically active age group  highest medical care
expenditures
+ Aging  gradual and steady reduction of muscle size and strength  lower
limb muscles
+ Progressive muscle weakness  ability perform daily tasks, personal
independence, higher risk of falls, hospitalization and mortality

4. Introduction
+ Treating/ reversing age-related decline  important  regular
exercise
+ NMES (Neuromuscular electrical stimulation)  application an
electric current with surface electrodes on weakened but
otherwise normally innervated muscles for improving muscle
strength
+ Last two decades  volitional contractions (VC) and electrically
evoked contractions (EC) have frequently been the approach of
choice for reducing muscle weakness

5. Introduction
+ Both techniques (VC, EC)  stimulate and overload muscles with a
moderate to high intensity  exercise intensity  determining factor for +
results
+ The higher the muscle overload intensity  greater muscle size and
strength gains = higher NMES intensity  greater muscle size and strength
gains
+ Heterogeneity and individual variability  health status and physical function
levels  care and individual supervision  reduce orthopedic injury risks
and adverse effects  frail/ recently ill

6. Introduction
+ Limiting factor  high intensity NMES  discomfort associated
with peripheral stimulation
+ Volitional & low-intensity electrically evoked contractions 
safe alternative  + results
+ Low intensity exercises  attractive alternative & better
recommendation for physical activity for the elderly ,
participation , adherence, muscle soreness minimized, injury
reduced

7. Aim No study has been conducted using a
combined program of low-intensity NMES
exercises superimposed onto voluntary
contractions (NMES+) in older adults
Evaluate the effects of three different
resistance training programs (VC, NMES,
and NMES+)  low intensity
Outcome : physical performance, muscle
CSA and the capacity to perform daily
tasks in healthy older adults

8. Intervention
+ All groups  targeted major knee extension muscles over a 16-
week period in men and women aged 75 and older living at a
geriatric nursing home.
+ Hypothesized  all exercise groups would significantly improve
muscle CSA, physical performance and the capacity to perform
daily tasks from a short-term perspective, and that the NMES+
program would show the larger improvements.

9. Methods
Design : RCT Divided 4 groups
Evaluated : baseline,
end 4 months
intervention period 
same independent
assessors

10. Inclusion Criteria :
- aged ≥ 75
- able to ambulate independently
- able to communicate
- willing to stay  geriatric
nursing home for the next 6
months
Exclusion Criteria :
- lower extremity fracture
or a metal implant
- MMSE <24
- unstable cardiovascular
disease or a
neurological disorder
that could compromise
them from exercising

11. Participants

12. Randomization and blinding :computer-
generated random numbers
volitional contraction , n
= 22
1
NMES , n= 22
2
NMES + (
Neuromuscular
electrical stimulation
and voluntary
contractions )
N= 22
3
Control group (n=23)
4

13. Outcome measurements
+ Primary  mobility (TUG)  3 trials and the quickest time was recorded in seconds.
+ Secondary 
- Rectus femoris cross-sectional area (CSA) of right leg  portable ultrasound unit 
avarage 3 measurements
- Balance  Berg Balance Scale (BBS) max 56 (higher scores representing better
performance)
- Aerobic endurance  6MWT
- Barthel Index (BI)
- Upper body strength  hand dynamometer  dominant hand

14. Intervention
+ All groups : three weekly non-consecutive exercise
sessions for 16 weeks
+ @session : 30-35 min
+ Individually , close supervision of two PTs
+ All intervention sessions  same indoor room
+ Goal : all participants perform total 48 exercise sessions

15. Intervention
Highest value of weight lifted successfully was recorded as the
1RM.
Participants performed a single repetition with a weight they could
lift through a complete knee extension
Intensity of exercise in all groups  1 RM off knee extensors

16. VC group
+ Knee extension exercises both legs  ankle
cuff weights
+ Seated 90° knee and hip flexion and then the
leg was extended to a full knee extension
+ Three sets of fifteen repetitions in each leg
with a 3-minute resting period between sets.
+ Raise the weight in 1 s (concentric phase),
keep a full knee extension for 3 s (isometric
phase) and slowly lower the weight in 2 s to
the starting position (eccentric phase)
+ Intensity was set at 40% of 1RM.

17. NMES and NMES + groups
+ NMES technique consisted of the application of an electrical current to the neuromuscular
junction in order to generate evoked muscle contractions with participants asked not to
participate with voluntary contractions
+ NMES +  NMES + voluntary contraction
+ Electrical stimulus was applied through the skin of the thigh using surface electrodes connected
to portable device
+ 4 adhesive surface 5x5cm  distal medial and proximal lateral portions of the subject's anterior
thigh
+ F = 50 Hz, phase duration of 400 μ
+ Intensity was adjusted to tolerance
+ Ankle cuff weights set at 40% of 1RM

18. Control group
+ did not receive any intervention.
+ resume their ordinary daily living and not participate in any
kind of exercise program

19. Result

20. Baseline descriptive

21. + Adherence : 78% completed all sessions
+ no significant adverse effects were reported by any of the
participants

23. + In addition, ANOVA revealed a significant time effect for hand-grip strength (baseline vs 4-
month intervention; P = .044 and balance (BBS) (P = .044)
+ Within-group analysis
- significant improvements in the rectus femoris CSA in all intervention groups
- Mobility (TUG) showed significant improvements in the NMES+ group , no significant changes
in VC and NMES groups, and a significant decrease in the control group
- (BI) improved significantly in all intervention groups but not in the control group
- Balance : All intervention groups tended to improve, higher in NMES+, whereas the control
group scores tended to decrease
- No significant effects for the aerobic endurance. The 6MWT distance tended to increase in all
intervention groups, whereas in the control group it tended to decrease

24. Discussion
+ Develop relatively short-term exercise intervention, safe,
accessible, and easy to follow  help older adults living in
geriatric nursing homes to gradually reduce the age-related
decline in their physical condition
+ no major side effects reported
+ attendance rate at 4 months was 78% a rate considerably
higher than that for other facility-based individual exercise
programs (hong et al)  appropriate and well tolerated

25. Discussion
Results  rectus femoris CSA and the capacity to
perform daily tasks significantly increased in the three
intervention groups
NMES+ group  most significant improvement in
mobility and a better tendency to improve balance
performance

26. Discussion
Results  muscle size increase in rectus femoris CSA  VC
: NMES : NMES + = 16,3% : 30,4% : 42,1%
NMES >VC : percentage of muscle volume involved during
the exercise  specifically stimulate the superficial fibers of
the whole muscle volume
Henneman's “size principle”, during voluntary contraction,
motor units (MUs) are recruited in an orderly fashion from
small (slow) to large (fast) in relation to the stimulus intensity
During NMES  MU recruitment pattern has been defined as
a spatially fixed and temporally synchronous
NMES favors the activation of large and small MUs, imposing
a contractile activity of both MUs even at relative low
intensities

27. Discussion
+ Gain in muscle size : not automatically guarantee functional
performance improvements
+ Van dkk  significant muscle CSA gains in VC and NMES
groups were not accompanied by significant improvements in
mobility , aerobic endurance and balance
+ NMES+ group  significant improvement in mobility and better
gains in the balance performance  cumulative effects of both
techniques.

28. Discussion
+ Diminished hand grip strength  premature mortality,
disability and other health-related complications in older
adults
+ Results : no significant hand-grip improvement  may
represent an attenuation of age-related decline.

29. Limitation
+ relatively short duration of the intervention may have truncated
the time needed to achieve greater improvements
+ not assess the long term effect of the intervention
+ rectus femoris CSA was assessed using USG. Muscle volume
can be measured using a variety of techniques, including
computer tomography (CT) and magnetic resonance (MR) 
expensive equipment , exposure of the subjects to ionizing
radiation

30. Limitation
+ Rectus femoris  represents a part of the quadriceps
femoris  more appropriate to assess the whole
quadriceps muscle volume and/or to measure knee
extension strength.
+ Participants were healthy individuals living in a geriatric
nursing home, and are therefore not representative of all
older adults at large

31. Conclusion + short-term perspective, a low-
intensity NMES+ exercise
program may be useful to
improve physical performance,
rectus femoris CSA, and the
capacity to perform daily tasks
in older adults living in a
geriatric nursing home.
+ low- intensity NMES+ exercises
are useful to partially mitigate
the age- related consequences
in this study population

32. Critical Appraisal

33. PICO
P : healthy elderly aged 75 or
older
I : volitional contraction,
neuromuscular electrical
stimulation
(NMES),neuromuscular
electrical stimulation
superimposed onto voluntary
contractions (NMES+ )
C: ordinary daily living O : TUG, CSA rectus femoris,
hand grip strength, BBS,
6MWT, BI

39. What were the results?
NO
YES
YES

40. THANK YOU