R e s e a r c h A r t i c l e C a r d i o v a s c u l a r R e s p o n s e s t o E x e r c i s e T e s t s in S u b j e c t s w it h P o l i o m y e l i t i s : A P il o t S t u d y A B S T R A C T : P e o p le w ith p h y s ic a l d is a b ilitie s often e x p e rie n c e d ifficu lty in d iffe re n t a c tiv itie s o f d a ily livin g. E m p h a sis is u su a lly p l a c e d on th e ir m e d ic a l reh a b ilita tio n , a n d th ere is often little a tte m p t on m e e tin g the h ealth c a r e n e e d s a f te r th e y a r e d is c h a r g e d f r o m r e h a b ilita tio n f a c i l i t i e s . R e c o g n itio n o f th e h ea lth c a re n e e d s is r e q u ire d to p r o v id e e ffe c tive tr e a t­ m en t a n d f a c ilita te h ea lth p ro m o tio n a c tiv itie s . D e c r e a s e d m u sc le stren g th in th e lo w e r lim b s in v ic tim s o f p o lio m y e litis often resu lt in d iffic u ltie s in m o b ility. A s p a r t o f a la r g e r stu d y to e v a lu a te the im p a c t o f re g u la r a e r o b ic e x e rc ise on the q u a lity o f life o f in d iv id u a ls w ith p h y s ic a l d isa b ilitie s , th is p i l o t stu d y a tte m p te d to o b ta in in fo rm a tio n on so m e im m e d ia te re sp o n se s to the n in e-m in u te w a lk /ru n te s t a m o n g a g ro u p o f p e o ­ p l e w ith p h y s ic a l d is a b ilitie s d u e to p o lio m y e litis . C o m p a r e d to an a g e -m a tc h e d c o n tro l grou p, th ere w a s a h ig h e r c a r ­ d io v a s c u la r d e m a n d on in d iv id u a ls w ith p o lio m y e litis . The o u tc o m e w a s s u g g e s tiv e o f a n e e d to a s s is t th e s u b je c ts in c o n se rv in g e n e rg y d u rin g a m b u la tio n b y im p ro vin g en d u ra n ce. Thus in d iv id u a ls w ith p o lio m y e litis a re lik e ly to b e n e ­ f i t fr o m re g u la r a e r o b ic exercise. KOLAPO HAMZAT TK, BSc, M.ED, MNSP1 1 Department o f Physiotherapy, University o f Ibadan, N ige ria K E Y W O R D S : PO LIO M Y E L IT IS, H E A L T H P R O M O T IO N , P H Y S IC A L EXERCISE , DISABILITY. INTRODUCTION There has been significant em phasis in health care on primary prevention of disability rather than on prevention or reduction o f secondary health problems in people with disabilities (Rimmer, 1999). There is therefore little inform a­ tion, on. health, prom oting activities for people with disabilities. The aims o f health prom oting programs for people with disabilities are to reduce secon­ dary health problem s like hypertension and pressure sores, to maintain functional independence, to provide an opportunity for leisure and enjoyment, and to enhance the overall quality o f life by reducing environm ental barriers to good health. Physical exercise has been identified as a preventive health behaviour often employed as a strategy to improve health (Li and Yoshida 1998). Shephard (1991) highlighted some o f the im pact o f phy­ sical activity on people with disability. The benefits included im provem ents in self-esteem, self-efficacy, perceived health, and ability to perform activities o f daily living. A study was therefore initiated to evaluate the im pact o f regu­ lar aerobic exercise on the quality o f life of individuals with physical disabilities. The current pilot study attem pted to obtain inform ation on some im m ediate responses to an exercise test in a group o f people with physical disabilities due to poliomyelitis. Poliom yelitis is an acute viral infec­ tious disease caused by the neurophilic virus, known as poliovirus, that attacks the brain and the ventral horn cells of the spinal cord (Birk, 1993). The dam age to the-lower, m otor neurons, o f the spinal cord usually results in weakness, flaccid paralysis and atrophy o f the m uscle groups supplied by the affected segm ent o f the spinal cord, with resultant defor­ mity. The paralysis may affect the lower lim b m uscles only, low er lim bs and lower trunk m uscles (i.e. paraplegia), or both upper and low er lim bs. In b u l­ bar poliom yelitis, the poliovirus infects the m edulla oblongata and may result in dysfunction o f the sw allowing m echa­ nism along with circulatory and respi­ ratory distress, apart from m uscle para­ lysis o f the extrem ities (Grim by and Jonsson, 1994). The scientific and medical challenge posed by po lio m y elitis at the b e g in ­ ning of the tw entieth century was o f a com plexity similar to that o f Acquired Im m unized D eficien cy Syndrom e - AIDS (Wyatt, 1995). However, the advent o f Safk and Sabin virus vaccines in 1954 and 1962 respectively, put a check on the effect o f the debilitating virus. Adoption o f a resolution in 1988 by the W orld Health A ssem bly to eradicate poliom yelitis globally by 2 0 0 0 , and efforts geared towards achievem ent o f this goal, have resu lted in various degrees o f success in different countries (Klaucke et al, 1997; Okwo B ele et al, 1997). Prevention o f paralytic infection by poliovirus has .been shown to be" rem arkably effective using oral vacci­ nation with live attenuated virus. In spite o f the vaccination however, poliom yelitis is still a problem in the third world, especially for individuals already afflicted w ith paralysis who have to be physically and socially reha­ bilitated. The main im pact o f disability for most o f the patients is in m obility- related activities (Grim by and Jonsson, 1994). Victims o f poliom yelitis have complained o f fatigue, muscle weakness, reduced endurance and gait problem s (Lonnberg, 1993). Energy requirem ents o f ambulation when both lower limbs are paralysed have been investigated. M eta­ bolic rate was found to be at least three CORRESPONDENCE: T K H am zat Departm ent O f Physiotherapy College O f M edicine U niversity O f Ibadan Oyo State, N igeria SA Jo u r n a l o f Physiotherapy 2000 V o l 56 No 3 39 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 3. ) times more than the basal rate accom pa­ nied by significant increases in heart rate when patients am bulate with crutches. The physiotherapist utilises various physical m odalities to, am ong other things, strengthen the weak o r paralysed m uscles, prevent jo in t contracture and correct deform ities. The physiotherapist also prescribes the use o f supportive and assistive devises like a lumbar corset, spinal jacket, ring top caliper, crutches and walking sticks. In the physical rehabilitation o f vic­ tims o f poliom yelitis in Nigeria, it is uncommon to include health prom oting physical exercise program m es that may enhance cardio-respiratory conditioning o f the victims in order to im prove am bu­ latory ability. This may be due to a lack o f inform ation on the benefits o f such program s for individuals with polio­ myelitis. Rimmer (1999) earlier indicated a strong need to estab lish linkages betw een reh ab ilitatio n facilities and com m unity based fitness program s in order to extend the rehabilitation process into the com m unity. T h erefo re the specific aim o f this pilot study was to evaluate some simple im m ediate cardio­ vascular responses in individuals with poliom yelitis to the nine-m inute walk/ run test (M atthews, 1978) in order to infer the physical weakness or otherwise o f the subjects. The outcom e may pro­ vide a rationale basis for inclusion o f health prom oting physical exercise pro­ grams in rehabilitation interventions in individuals with a history o f lower limb muscle paralysis due to poliom yelitis. MATERIALS AND METHODS Two groups o f subjects participated in this study. The first group included 15 male and female patients (aged 7-27 years) with paralytic poliomyelitis affect­ ing both lower limbs, who were am bu­ lating each using a pair o f above-knee calipers and a pair o f crutches. The sub­ jects did not have a history o f partici­ pating routinely in physical activities. Each participant in the first group was m atched for age with normal partici­ pants in the second group who served as control. Also, the 15 male and fem ale subjects in the control group (aged 7-27 years) did not have a history o f partici­ pating routinely in physical activities. PROCEDURE On each day o f adm inistration o f the test, the follow ing data were collected from subjects from the two groups: Age (years): the chronological age of each subject was recorded in years as age at the last birthday. H eight (cm): W ith the subject in supine lying on a plinth, height was mea­ sured as the vertical distance between the vertex o f the head to the inferior border o f the heels o f the feet. This tech­ nique was used because o f the inability o f the polio patient to stand erect w ith­ out calipers. The same procedure was also used for subjects in the control group. W eight (kg): Body w eight was m ea­ sured using a conventional portable w eighing scale. Due to the inability o f the paraly tic polio p a tie n t to stand unsupported, each patient stood on the scale, putting on the pair o f calipers and supported by a pair of crutches. The total weight was recorded. The patient disem ­ barked from the scale and the supporting aids were m easured alone. Weight o f the aids was subtracted from the total weight to get the patient’s body weight. The subjects in the control group w ere w eighed directly on the scale. Each sub­ ject wore a vest and a pair o f shorts when the body weight was being determined. Blood pressure (mmHg) and heart rate (beats/min): The resting cardiovas­ cular variables were m easured after each subject had rested for a m inim um period o f ten minutes. The blood pressure was m easured, with each subject in the sit­ ting position using a sphygmomanometer and stethoscope. H eart rate was counted as pulse rate at the radial artery on the subject’s left wrist using a stop-watch. THE EXERCISE TEST Each individual with poliom yelitis was allowed to put on the pair of calipers, and was instructed to walk, or fast-walk, or run at his/her own com fortable, self­ selected walking velocity with the aid o f a pair of crutches. The self-selected velocity was reported to be the most efficient walking speed from an energy conservation point o f view (Nielson et al, 1990). The stop-watch was started and at the 9th m inute the patient was asked to stop the am bulation exercise, and the blood pressure and heart rate were m ea­ sured. Throughout the course o f the 9- minute walk/run, subjects were closely monitored by the researcher to avoid any untoward physical and medical incidents. TREATMENT OF DATA From the measurements taken, the rate pressure product was com puted for each participant before and after the exercise test. rate pressure product = systolic blood pressure x heart rate F o r all the variables determ ined, means and standard deviations were com puted. The independent t-test was utilized to com pare the resting and post exercise param eters o f the polio patients and their age-m atched control subjects (Bailey, 1991). The level o f significance was set at p<0.05. RESULTS The physical characteristics o f the sub­ jects in the two groups are shown in table 1, indicating a significant difference (p<0.05) in the mean height and body weight. The mean resting rate pressure product o f individuals with poliomyelitis was significantly higher (p<0.05) than that o f the control group (Table 2). Com paring the im m ediate post exercise cardiovascular param eters o f the sub­ jects, the mean values o f the heart rate and rate pressure product o f individuals w ith poliom yelitis w ere significantly higher (p<0.05) than corresponding val­ ues in the control group (Table 3). The mean heart rate o f individuals with polio­ myelitis increased by alm ost 21% im m e­ diately after the 9-m inute walk/run test, but there were no appreciable changes in the systolic and diastolic blood pres­ sures. Similarly, there were no significant changes in the cardiovascular parameters in the control group. DISCUSSION P eople with physical disabilities are highly susceptible to secondary health conditions affecting, among others, fit­ ness and endurance. Health prom oting strategies would reduce or elim inate these secondary health problems. Rimmer (1999) indicated that most professionals get little training in exercise prescription for people with disabilities. The author recom m ended that the major com po­ 40 S A Jo u r n a l o f Physiotherapy 2 0 0 0 V o l 5 6 N o 3 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 3. ) Table 1. Physical characteristics o f subjects. REFERENCES Physical parameters G roup 1 mean(sd) Control mean(sd) t value p level Height (cm) 133.0(15.8) 163.4(22.9) 4.23 0.0 0 0 * W eight (kg) 41.9(12.1) 55.7(11.1) 3.2 77 0.0 0 3 * BMI 23.8(6.7) 21.1(3.1) 1.44 0.1 5 9 ’ Statistically significant (p<0.05) Table 2. Resting cardiovascular parameters o f the subjects. Cardiovascular parameters G roup 1 mean(sd) Control mean(sd) t value p level Heart rate (b/m in ) 73.6(15.1) 75.6(10.3) 0 .4 2 4 0.6 75 SBP (mmHg) 106.1(13.5) 103.8(7.6) 0.581 0.5 6 6 DBP (mmHg) 64.4(9.5) 68.9(10.8) 1.201 0.2 4 RPP 9 0 88.3(1279.7) 7 9 50 .4 (10 84.3 ) 2.6 2 7 0.0 1 4 * ’ Statistically significant (p<0.05) SBP = Systolic blood pressure, DBP = Diastolic blood pressure, RPP = Rate pressure product Table 3. Im m ediate post exercise cardiovascular parameters. Cardiovascular parameters G roup 1 mean(sd) Control mean(sd) t value p level Heart rate (b/m in ) 88.9(18.1) 72.7(6.6) 3.268 0.0 0 3 * SBP (mmHg) 108.7(13.7) 108.5(7.8) 0 .0 4 9 0.961 DBP (mmHg) 66.5(9.9) 69.3(7.1) 0.891 0 .3 8 0 RPP 97 22.3(2068.4) 7899 .5 (10 60.7 ) 3.0 37 0 .0 0 5 * ’ Statistically significant (p<0.05) SBP = Systolic blood pressure, DBP = Diastolic blood pressure, RPP = Rate pressure product nents o f a fitness program for people with disabilities should include cardio­ vascular endurance. In the current study, the rate pressure product was the only resting cardiovas­ cular param eter that was significantly d ifferen t betw een the subjects with poliom yelitis and the control subjects. The post exercise heart rate and rate pressure product w ere significantly higher in the poliom yelitis subjects. H eart rate has been reported to have 'a linear relationship with oxygen demands o f the heart (Kispert, 1987). Therefore there was a higher oxygen dem and on the hearts o f p o liom yelitis subjects while they were taking part in the nine- minute walk/run test. This observation was further reinforced by the signifi­ cantly higher post-exercise rate pressure product in subjects with poliomyelitis. Rate pressure product is a useful index o f cardiac stress and a valid predictor o f m yocardiac oxygen consum ption (Kispert, 1987). These outcom es are suggestive o f a need to assist the subjects in conserving energy during ambulation by improving endurance. Physical acti­ vity has been identified as a very cost effective, as well as more enjoyable, health prom otive measure in individuals with physical disability (Katsum ura and Hinman, 1997). CONCLUSION Preventing secondary health conditions by em pow ering people with physical disabilities to take control o f their own health will be more cost-effective than watching them decline in function from a lack o f good health m aintenance. Physiotherapists should join in the collec­ tive effort to enrich the lives o f people with disabilities. Therefore, the inclusion o f exercise training program s that will enhance cardio-respiratory conditioning in victims o f poliom yelitis is advisable in order to reduce the energy dem and in am bulatory activities. The changes will also enhance the quality o f life o f the affected individuals (Rimmer, 1999). ( ACKNOWLEGEMENT The author acknowledges the editorial assistance given by Prof. Dele Amosun of the Department o f Physiotherapy, Uni­ versity o f the Western Cape, South Africa, in the preparation o f this manuscript. Bailey DM 1991 Research for the health professional - A practical guide. FA D avis Company Birk TJ 1993 P oliom yelitis and post polio- syndrome: Exercise capabilities and adapta­ tions, current research, future directional and w idespread applicability. M ed icin e and Scien ce in Sports and E xercise 25(4): 466-472 Grimby G, Jonsson AL 1994 Disability in poliom yelitis sequels. Physical Therapy 74 (5): 4 1 5-424 Katsumura T, Hinman A D 1997 Longer healthier lives. World Health 4: 31-34 Kispert CP 1987 Clinical measurement to assess cardiopulmonary function. Thysical Therapy 76: 18 8 6 - 1890 Klaucke DN, Lobanov A, O kwo B ele JM, Barakamfitiye D 1997 Status o f polio eradi­ cation in the seven countries o f the Eastern Africa E pid em iological Block. Journal o f Infectious D iseases 175 Supp. I: S16-S 19 Li A, Yoshida K 1998 Women with physical disabilities and their health: Implications for health prom otion and ph ysical therapy. Physiotherapy Canada Fall: 309-315 Lonnberg F 1993 Late onset polio sequelae in Denmark. Scandinavian Journal o f R ehabili­ tation and M edicine Supp 28: 7-15 M athews D K 1978 M easurem ents in P hy­ sical Education. 5th Ed. Philadelphia, WB Saunders Company N ielson DH, Harns JM, Minton YM , M otely NS, R ow ley JL, Wardsworth CT 1990 Energy Cost, exercise intensity and gait efficiency o f standard versus rocker bottom axillary crutch walking. Physical Therapy 70: 487-493 Okwo Bele JM, Lobanov A, Biellik RJ, B ir­ mingham ME, Pierre L, Tomori O, Barakam­ fitiye D 1997 Overview o f poliom yelitis in the African. Region and current regional plan o f action. Journal o f Infectious D iseases 175 Supp 1: S I0 -S 1 5 Rimmer JH 1999 Health promotion for people with disabilities: The emerging paradigm shift from disability prevention to prevention o f secondary conditions. Physical Therapy 79: 495-502 Shephard RJ 1991 B enefits o f sport and physi­ cal activity for the disabled: im plications for the individual and for society. Scandinavian Journal o f Rehabilitation M edicine 23: 51-59 Wyatt HV 1995 Poliovaccines: Lessons learnt and forgotten. History and Philosophy o f the Life Scien ce 17 (1): 91-112 SA Jo u r n a l o f Physiotherapy 2000 V o l 56 No 3 41 R ep ro du ce d by S ab in et G at ew ay u nd er li ce nc e gr an te d by th e P ub lis he r (d at ed 2 01 3. )