To Study the Effect of Mental Practice on One Leg Standing Balance in Elderly Population

274 Indian Journal of Physiotherapy & Occupational Therapy. January-March 2013, Vol. 7, No. 1

To Study the effect of Mental Practice on one Leg StandingBalance in Elderly Population

Vidya V Acharya1, Saraswati Iyer2

1M.P.Th., 2Professor, Seth G.S.Medical College & K.E.M. Hospital, Parel, Mumbai

ABSTRACT

Purpose of study is: to compare "effect of only physical practice" with " effect of physical practice andmental practice" in subjects, for activity of one leg standing.

Materials used: table, chair, cassette and record player, stop-watch, newspaper.

Methodology: 80 independently ambulatory subjects (age group 50-70yrs) were randomly selectedand divided into 2 intervention groups of 40 each. Task was to stand on the preferred leg with arms byside and one legged balance time was measured. Two sessions (1st & 2nd) of the task, of 5 days each,were given to subjects at a periodic gap of 30 days. Baseline and final measurements of one leggedbalanced time were compared after a three days practice intervention period.

Group I (n=40, 20 male s and 20 females) performed only physical practice in both sessions (1st & 2nd)and Group II, (n=40, 20 males and 20 females) performed only physical practice in 1st session and in2nd session performed physical practice interspersed with mental practice. Mental Practice involveduse of idealized visual and kinesthetic mental images provided to subjects through recorded tape.

Results: Percentage improvement in balance time in both sessions was compared and statistical analysiswas done by paired 't' test and 'z' test. All groups showed improvement, but Group II showed the mostimprovement in 2nd session, of 33.01% in males and 31% in female's resp. ('p' < 0.001). Comparison ofpercent improvement between Group I and II, showed an increment of 10% in balance time of group IIin its 2nd session('p' < 0.001,HS).Thus showing that balance time increased significantly with physicalpractice interspersed with mental practice.

Conclusion: Our study concludes that Mental Practice along with Physical Practice may hence be animportant therapeutic tool to encourage rapid acquisition of a motor skill.

Keywords: Mental Practice, Physical Practice, One Leg standing Balance

INTRODUCTION

Major concern of physical therapist is movement –its acquisition, quality and retention. Primary aim ofphysical therapist is to maximize patient’s movementpotential. So focus is on physical techniques, forteaching new motor skills to patients.1 However it isnot always possible to carry out task under guidance oftherapist.

Hence Mental practice, which is cognitive rehearsalof a physical skill in absence of any gross muscularmovement, can be an utilized as a clinical tool inassisting patients, to rapidly learn a motor task. 1

A major concern of physical therapists with allpatients, but especially with elderly, is balance. Theincreased postural sway seen with age is correlated

with loss of balance and increased incidence of falls inelderly2.Therefore, balance is selected as physical taskto test the effect of mental practice on.

MATERIAL AND METHOD

Materials

Table, chair, cassette and record player, stop-watch,newspaper.

ii. Method

a. Inclusion Criteria

Age group: 50 to 70 years.

All subjects are independently ambulatory withoutassistive device.

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Indian Journal of Physiotherapy & Occupational Therapy. January-March 2013, Vol. 7, No. 1 275

b. Exclusion Criteria

Subjects with orthopaedic, neurological,uncontrolled diabetes, uncontrolled blood pressureproblem, significant hearing and vision loss andpsychological problems were excluded.

c. Selection of Subjects

Group Subjects Sex Number Age Mean Age(yrs) (yrs)

I PP and ONLY PP FM 2020 50-70 59.22

II PP and PP + MP 2020 2020 50-70 59.12

PP=PHYSICAL PRACTICE

MP=MENTAL PRACTICE

d. Study Procedure

A short verbal health care history was taken.

SESSION I

Each subject from group I and group II stood onpreferred leg and lifted other foot. Arms were held byside and time was measured using a stopwatch untillifted foot contacted ground.

An average of three readings of measured time wastaken to have a baseline value on day 1. Group I & IIsubjects carried out physical practice of activity for nextthree days. Final value of balance time was taken froman average of three readings on day 5. On day 2,3,4:reading task was given, which distracted attention fromoriginal activity. So on day 2,3,4 group I & II subjectstook:

PHYSICAL Reading PHYSICAL Reading PHYSICALPRACTICE Session PRACTICE Session PRACTICE

SESSION II

After a month Group I subjects took only physicalpractice same as they took in previous month.

Group II took physical practice and mental practiceof the activity.

Baseline and final measurements of balance time ofboth groups were taken again on day 1 and day 5respectively.

Group II subjects listened to recorded speechthrough record player. Speech consisted of detailsregarding balance activity & relaxation. The capabilityof subjects to concentrate and perceive recorded speechwas measured on Likert’s scale.

Likert’s Scale

1. did not understand

2. understood little

3. understood satisfactorily

4. understood properly

5. understood properly and completely.

Group II subject’s Likert’s scale response was 4,5after tape session.

So on day 2, 3, 4 group II subjects took

PHYSICAL Tape PHYSICAL Tape PHYSICALPRACTICE Session PRACTICE Session PRACTICE

FINDINGS

Results And Observations

Percent improvement in balance time in bothsessions was compared and statistical analysis wasdone by paired‘t’ test and ‘z’ test.

Group I (Males)

Day 1 Day 5 % improvement t- value p- value

P. P1st 54 ± 36.57 62.15 ± 37.13 17.45 ± 10.37 7.52 < 0.001session

P. P 2nd 55.95 ± 36.78 67.60 ± 38.56 21.88 ± 10.97 8.89 < 0.001session

During 1st session,% improvement in response forbalance time is 17.45.This increase is statistically highlysignificant at p<0.001,which indicates response on day5 is likely to be much more as compared to day 1 due tophysical practice.

During 2nd session,% improvement in response forbalance time is 21.88.This increase is statistically highlysignificant at p<0.001,which indicates response on day5 is likely to be much more as compared to day 1 due tophysical practice.

Group I (Females)


P. P1st 59.85 ± 44.70 70.65 ± 46.54 19.25 ± 10.62 7.52 < 0.001session

P. P 2nd 62.30 ± 45.96 78.20 ± 49.48 23.99 ± 12.30 8.89 < 0.001session

During 1st session,% improvement in response forbalance time is 19.25%.This increase is statisticallyhighly significant at p<0.001,which indicates responseon day 5 is likely to be much more as compared to theday 1 due to physical practice.

During 2nd session,% improvement in response forthe balance time is 23.99%.This increase is statisticallyhighly significant at p<0.001,which indicates responseon day 5 is likely to be much more as compared to day1 due to physical practice.



Group II (Males)


P. P1st 50.30 ± 29.30 61.65 ± 34.97 19.48 ± 9.98 8.27 < 0.001session

P. P + 52.75±29.89 77.20 ± 40.57 33.01 ± 11.86 12.44 < 0.001M.P2nd

session

During 1st session,% improvement in response forbalance time is 19.48%.This increase is statisticallyhighly significant at p<0.001,which indicates responseon day 5 is likely to be much more as compared to day1 due to physical practice.

During the 2nd session,% improvement in responsefor balance time is 33.01%.This increase is statisticallyhighly significant at p<0.001,which indicates responseon day 5 is likely to be much more as compared to day1 due to physical practice and mental practice.

Group II (Females)


P. P1st 52.60 ± 39.51 61.85 ± 41.38 19.00 ± 10.001 8.48 < 0.001session

P. P + 55.60 ± 38.46 77.30 ± 42.73 31.79 ± 12.86 11.04 < 0.001M. P2nd

session

During 1st session,% improvement in response forbalance time is 19%.This increase is statistically highlysignificant at p<0.001,which indicates response on day5 is likely to be much more as compared to the day 1due to physical practice.

During 2nd session,% improvement in response forbalance time is 31.79%.This increase is statisticallyhighly significant at p<0.001,which indicates responseon day 5 is likely to be much more as compared to theday 1 due to physical practice and the mental practice.

Comparison of Average % Improvement Between 1st and 2nd Session in Males and Females.

Subjects % % % Difference t- value p- valueImprovement I Improvement II improvement

Group I Males PP 17.45 21.88 4.33 8.18 P < 0.001

FemalesPP 19.25 23.99 4.74 6.74 P < 0.001

Group II MalesMP + PP 19.48 33.01 13.53 11.67 P < 0.001

FemalesMP + PP 19.00 31.79 12.79 11.91 P < 0.001

From above table maximum improvement is seen with Group II carrying out physical practice and mental practicein second session.

Comparison of Overall Average % Improvement Between Group I and Group II in the 1st and 2nd Session.

Group-I Group-II z- value p- value(M+F) (M+F)

% Improvement1st Session 18.35 + 10.49P.P 19.24 + 9.999P.P 0.3 NS

% Improvement2nd Session 22.93 + 11.69P.P 32.4 + 12.37P.P 3.53 P < 0.001(HS)

From above table we can infer that

Comparison between Group I and II is statisticallynot significant in first session, which indicates thatoverall improvement between both groups is the same.Difference between them is 0.89%, which is not up tothe level of significance.

Irrespective of sex of the subjects, physical practiceis not enough to increase response in 2nd session forsubjects in group I.But with supplement of mentalpractice response in 2nd session for subjects in group IIincreased by 10%.This increase is statistically highlysignificant p<0.001, which indicates that physicalpractice and mental practice is likely to yield much more

response in 2nd session as compared to only physicalpractice.

Mental Practice interspersed with Physical practicesignificantly improved balance time in the study.

The difference between comparative groups showedhighly significant results:

• Within groups

All groups showed improvement, but the Group IIshowed the most improvement in

2nd session of 33.01% in males and 31% in femalesrespectively.



• Between both groups

The comparison of percent improvement in Group Iand II, showed an increment of 10% in balance time ofgroup II in its 2nd session. Thus showing that thebalance time increased with physical practice andmental practice of the activity.

Following could be the reasons for significantincrease in balance time for Group II subjects.

Strengthening of Engram Formation

The plausibility that improvement in performanceis a direct function of mental practice is related to engramformation. Program of engram formation3 includes i)Perception ii) Precision iii) Perceptual practice.

PERCEPTION

While carrying out, the act of standing on one leg,perception of sensory inputs are mainly from:proprioception, vision and auditory stimulus from tapesession, which provides information aboutperformance to cerebellum and automatic monitoringcentre.

Mental imaging during tape session and physicalpractice facilitate process of engram formation, thusenhancing motor learning. This is evident fromresponse of Group II in 2nd session. For Group 1 subjects,it can be inferred that, engram process is notstrengthened as those subjects carried out an activity,not related to one leg standing, during reading session.

Imaging studies by Shadmer and Holcomb haveshown cerebellum to be active during consolidation ofa learned internal model of a task4. It acts as adaptivefeed forward control system, which programs voluntarymovement skills, based on memory of previous sensoryinputs and motor outputs.

PRECISION

Precision of one leg activity is enhanced by mentalpractice, which entails picturing of standing on oneleg, while imagining kinesthetic feel of act and trying tobalance on one leg and at the same time correctingimagined mistakes. This occurs in addition to actualphysical performance of activity.

Perceptual practice

Results into excitation of desired neuronal linkagesand inhibition of those motor neurons, which should

not be performing in pattern of the one leg standingactivity. This helps into minimizing leg muscle work &facilitating muscle work with appropriate force anddirection5, thus developing a more efficient balance &co-ordination.

So Mental Practice substitutes Physical Practice inprocess of engram formation. This image would thencreate a perception of motor act, that would activate“automatic monitoring center” and facilitateconsolidation of engram formation.

With engram development, volitional excitation4

takes place, which is strengthened during PhysicalPractice of the activity and this adds for improvementin performance in Group II.

Effect of Auditory Stimulus

• Mental Practice given in form of auditory cue helpedin facilitation of mental picture, by guiding activityof balancing on one leg.

• Use of background music induces relaxationresponse.

• Commands used during tape session affect toneregulation, attention, arousal. This in turn enhancesperformance by increasing focus to be achieved4.

EFFECT OF PRACTICE

During Physical Practice

Subjects carry out Procedural learning6 i.e. repeatedexposure of activity-hence strategies applicable tochanging stimulus configuration, within task must beacquired through practice.

Procedural Learning is supported by circuitsinvolving Prefronto-caudate-striosmal topographicprojections6 . Saint and Taylor propose that straitum’srole involved with mobilizing new procedures to selectamong known procedures by acting as proceduralmemory buffer7 .

i. During Mental Practice

Subjects carry out Perceptual learning & Declarativelearning. Declarative learning results in ability tostore and consciously recall tape session duringactual practice session.

Temporal-cortico-caudate projections are involved(neo striatum)6.



iii. Acquisition of procedural knowledge throughrepeated practice may eventually result intodevelopment of declarative knowledge of task.

iv. Conversely development of declarative knowledgeof task may hasten acquisition of proceduralknowledge8.

v. With repetitive information through mental andphysical input, Group II showed significantimprovement in average balance time during secondsession.

This improvement in the task can be supported bythe research:

Neuro-imaging Studies

• In mental simulation of motor act, cerebral bloodflow studies suggest that prefrontal cortex,supplementary motor area, basal ganglia,cerebellum, structures required for performance ofactual movement, are active5.

• PET studies have shown changes in local cerebralblood flow associated with state of informationprocessing i.e. activation when hearing words.(Stephan H Koslow, George V. Coelho)9

Effect on Memory Function

• Hippocampus10 provides drive that causestranslation of short term memory to long term i.e. ittransmits signals which seems to make mindrehearse over & over new information.

• Consolidation of long term memory of verbal typetakes place within hippocampi.

Effect of Motivation

• Motivation hypothesis postulates that MentalPractice increases the subject’s motivation toimprove1.

• Following structures are involved in motivation:prefrontal cortex, limbic structures, hypothalamus,thalamus, brainstem, motor cortex (structures arealso active during mental practice)11.

Effect of Neurotransmitter Activity

• Noradrenergic, dopamine, serotonin systemsinfluence operations of neural systems for decisionmaking12.

• These systems have cognitive appraisals oftenwithout conscious awareness.

CONCLUSION

• In elderly population, Mental Practice coupled withPhysical Practice has shown to improve one legbalance time more significantly than PhysicalPractice alone.

• This improvement in balance, which is fundamentalcomponent of human movement, suggests thatMental Practice has promising usefulness in healthcare.

• Because efficacy of mental practice increases withincreasing task familiarity, it could be usefulmodality for rehabilitation.

• Therapeutic exercise could be supplemented withmental imaging during rest period.

• Patients confined to bed can use visualizationtechniques to prepare for future retraining in gaitand activities of daily living.

• It could easily be incorporated into patient’s homeprogram.

• Mental rehearsal encourages patients to assumeresponsibility for their recovery.

• Thus, Mental Practice may be an importanttherapeutic tool to encourage rapid acquisition of amotor skill.

ACKNOWLEDGEMENT

My heartfelt thanks to the Dean of Institute, Head ofPhysical Therapy Department, Bio-statistician, all mysubjects, departmental staff and colleagues.

Conflict of Interest - Nil.

REFERENCES

1. Claudia, L.Fansler, Cathy L. Poff, Katherine FShepard: Effects of mental practice on balance inelderly women. Physical Therapy, September1985, Vol.65, No.9.

2. Antonio Nardone, Rosella Siliotto: Influence ofaging on keg muscle reflex response to stanceperturbation. Arch Phys Med Rehabilitation,February 1995, Vol 76.

3. Frederic J Kottke, Daniel Halpern: The training ofco-ordination.Arch phys Med Rehabil, December1978, Vol.59.



4. Darcy A Umphred: Interventions for NeurologicalDisability, Neurological Rehabilitation 4 th Ed.

5. Janet Carr, Roberta Shepherd: Training motorcontrol, increasing strength and fitness andpromoting skill acquisition, NeurologicalRehabilitation. Optimising Motor Performance.

6. J.A.Saint–Cyr, Ann.E.Taylor, A.E.Lang: ProceduralLearning and Neo-straital Dysfunctions in man,Brain 1988, 111,941-959.

7. P.Soliveri, R.G.Brown, M.Jahanshahi: Learningmanual pursuit tracking skills in patients withParkinsons’s Disease. Brain 1997, 120, 1325-1337.

8. Pascual Leone, J Grafman, K.Clark,M.Stewart:Procedural learning in Parkinson’sDisease and Cerebellar Degeneration.Annals ofNeurology,July-Dec 1993,Vol.34,1-6.

9. Stephan H.Koslow, George V.Coelho: FunctionalMapping of the Human Brain.Decade of the Brain.

10. Guyton and Hall: Behavioral and MotivationalMechanisms of the Brain. Textbook of Medicalphysiology.9th Ed.

11. Paul D Cheney: Role of cerebral cortex in voluntarymovements.A Review. Physical Therapy, May1985, Vol65, No5.

12. R E O’Caroll, B P Papps: Decision making inHumans: The Effects of manipulating the centralnoradrenergic systems.J Neurology NeurosurgeryPsychiatry 2003:74:376-378.


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To Study the Effect of Mental Practice on One Leg Standing Balance in Elderly Population