Ph ysic al F itne ss a nd

He alth y Lo w Ba ck F unct ion

Sh aron Ann Plo wman 

NOR THER N ILL INOI S UNI VERS ITY

ORIGINALLY PUBLISHED AS SERIES 1, NUMBER 3, OF THE PCPFS RESEARCH DIGEST.

HI GHLI GHT

Th e d e velo p m en t a n d m a in t e n a n c e of h e a lt h y lo w ba ck

fu n ct i on re qu ir es a ba la n c e of fl exib ilit y, st ren g t h , a n d

en d u ra n ce. Sp ecif ica l ly, t h e cr it ic a l co m p on en t s a r e:

a . lo w ba ck lu m ba r fl exib ilit y;

b. h a m st r in g fl exib ilit y;

c. h i p fl exor fl exib ilit y;

d . st ren g t h a n d en d u ra n ce of t h e fo rwa r d a n d la t era l

a b d om i n a ls ; a n d

e. st ren g t h a n d en d u ra n ce of t h e ba ck ex t en s or m u scle s.

In clu d e a p p rop ria t e ex erci ses fo r ea ch gr ou p in yo u r wo rkou t s,

p a yin g p a rt ic u la r a t t en t ion t o yo u r p e rson a l we a kn e sses .

Papers 6 and 7 in Section II gave a general overview of the benefits of physical activity and

how those benefits related to major lifestyle diseases and the Healthy People 2000 promotion

and disease prevention priorities. This paper focuses on physical activity, physical fitness,

healthy back function, and low back pain.

The following key points are discussed in detail in this article:

■At some time in their lives, 60–80% of all individuals experience low back pain. The

condition is disabling to 1–5% of this population.

■To have a healthy, well-functioning back, flexible lumbar muscles, hamstrings, and hip

flexors, and strong fatigue-resistant abdominal and back extensor muscles are necessary.

■The Healthy People 2000 goals aim to decrease disability from chronic disabling disease

and to increase the proportion of the population who regularly perform activities to

enhance muscular strength, endurance, and flexibility. In terms of low back health, the

latter goal may be one way of achieving the former goal.

■Exercises to maintain or increase muscular function in the low back region are presented in

Table 13.1.

■The anatomical logic (presented in Table 13.2) linking low back health and physical activity

is stronger than the research evidence at this time.
TA BLE 1 3 .1

Su g g es ted ex er ci ses f o r v a r iou s f i tn es s le v els .

NE UROM USCU LAR FITN ESS COMP ONEN TS

a. Lu mbar mob ilit y*

b. Ha mstr ing flex ibil ity*

c. Hi p fl exor fle xibi lity *

d. Ab domi nal stre ngth /end uran ce** 

e. Ba ck e xten sor stre ngth /end uran ce** 

LO W

Kn ee t o Ch est

In supine lying position bring one or both knees to the chest, grasping the leg, under the thigh(s), raise 

and lower head slowly.

Mo difi ed H urdl er’s Str etch 

Si t wi th o ne l eg s trai ght, the oth er f lexe d. M ove the flex ed k nee to t he s ide and bend for ward .

Hi p Ex tens ion

St and with pel vis in n eutr al p osit ion. Ext end leg back ward at hip. 

Pe lvic Til t

In sup ine lyin g or sta ndin g po siti on—p ress pel vis to f loor or wall .

Hy pere xten sion —1

Ly ing in p rone pos itio n wi th h ands at thig hs. Keep nec k an d ch in i n ne utra l po siti on and raise shoulders off

fl oor. 

MO DERA TE

“M ad C at”

Kn eeli ng o n al l fo urs alte rnat e he ad u p wi th s way back and hea d tu cked wit h ro unde d ba ck.

PN F Su pine Pos itio n

Pl ace jump rop e ar ound foo t or ank le w ith leg rais ed a s st raig ht a s po ssi- ble . Co ntra ct a gain st r ope, rel ax,

an d pu ll l eg s trai ghte r. R epea t.

Ly ing Stre tch

Li e on tab le w ith knee s ov er t he e dge and back fla t. P ulli ng o ne l eg t o th e ch est (han ds o n th igh) str etch es

th e op posi te h ip.

Pa rtia l Cu rl ( crun ch)

Ho ok l ying pos itio n, f eet not held , ti lt p elvi s, c url up, slid ing hand s at sid e 3– 41/2 i nche s.

Hy pere xten sion —2
Ly ing in p rone pos itio n wi th a rms and hand s ex tend ed f orwa rd. Keep nec k an d ch in i n ne utra l po siti on a nd

ra ise shou lder s of f fl oor. 

HI GH

Cr osse d Le g Fl exio n

Si ttin g po siti on w ith knee s fl exed and ank les cros sed. Slo wly bend for ward unt il h ead appr oach es f loor .

St andi ng S tret ch

St and with one leg pla ced on a sup port at abou t 90 ° hi p fl exio n. K eepi ng b ack stra ight wit h sh ould ers

ba ck, flex for ward .

St andi ng S tret ch

St and in f orwa rd b ackw ard stri de p osit ion. Ben d fr ont knee and thr ust back hip for ward . Ke ep f ront kne e

ov er a nkle .

Ob liqu e Cu rl

Ly ing on s ide — tw ist trun k an d cu rl u p re achi ng f or t op l eg w ith oppo site arm .

Hy pere xten sion —3

Lying in prone position on a table or bench with body supported and stabilized from top of pelvis down. Flex

waist to 90° and extend to several inches above level.

TA BLE 1 3 .2 

Th eor e tica l r e lati on sh ip b e twee n p h y sic al f i tn es s co m p on en ts an d

h e alth y / u n h eal th y lo w b a ck / s p in a l fu n cti on .

Ph ysic al F itne ss C ompo nent 

Ca rdio vasc ular Res pira tory End uran ce

Bo dy C ompo siti on

Ne urom uscu lar

a. Lu mbar fle xibil ity

b. Ha mstr ing flex ibil ity

c. Hi p fl exor fle xibi lity 

d. Ab domi nal stre ngth /end uran ce

e. Ba ck e xten sor stre ngth /end uran ce

Normal Anatomical Function i n Low Bac k—He al t h y

Di scs obta in n utri ents and dis pose of wast es b y ab sorp tion fro m ad jace nt b lood sup ply. 

Hi gh m uscu latu re a llow s fo r pr oper fun ctio ning as outl ined bel ow a nd p rovi des mech anic al l oadi ng o n th e

ve rteb rae for main tena nce of b one mass .

Al lows the lum bar curv e to be almo st r ever sed in f orwa rd f lexi on.

Al lows ant erio r ro tati on ( tilt ) of the pel vis in f orwa rd f lexi on a nd p oste rior rot atio n in sit ting pos itio n.

Al lows ach ieve ment of neut ral pelv ic p osit ion. 

Ma inta ins pelv ic p osit ion; rei nfor ces back ext enso r fa scia and pul ls i t la tera lly on f orwa rd f lexi on

pr ovid ing supp ort. 

Pr ovid es s tabi lity for spi ne; main tain s er ect post ure; con trol s fo rwar d fl exio n.

Dy sfun ct i o n
Po or c ircu lati on, low CVR endu ranc e; a ther oscl eros is

Hi gh % bod y fa t co nten t

In flex ible 

In flex ible 

In flex ible 

We ak, easi ly f atig ued

We ak, easi ly f atig ued

Re sul t s of Dys func t i on —Unh eal t hy

Ma y sp eed up d isc dege nera tion .

In crea ses the weig ht t he s pine mus t su ppor t; m ay l ead to i ncre ased pre ssur e on dis cs o r ot her vert ebra l

st ruct ures .

Di srup ts f orwa rd a nd l ater al m ovem ent; pla ces exce ssiv e st retc h on ham stri ngs, lea ding to low back and 

ha mstr ing pain .

Re stri cts ante rior pel vic rota tion and exa gger ates pos teri or t ilt; bot h ca use incr ease d di sc c ompr essi on;

ex cess ive stre tchi ng c ause s st rain and pai n.

Ex agge rate s an teri or p elvi c ti lt i f no t co unte ract ed b y st rong abd omin al m uscl es, ther eby incr easi ng d isc

co mpre ssio n.

Al lows abn orma l pe lvic til t; i ncre ases str ain on b ack exte nsor mus cles .

In crea ses load ing on s pine ; ca uses inc reas ed d isc comp ress ion. 

Studies (see body of text) support the fact that individuals who have suffered low back

pain (LBP) have weaker, more fatigable, and less flexible muscles in the trunk region even

after the acute pain episode has subsided than do those who are pain free. Continued

weakness, low endurance, and restricted range of movement appear to be contributing factors

to recurrent LBP. The ability to predict first-time LBP from muscular strength, endurance, or

flexibility values has not been established. Likewise, a direct relationship between LBP and

cardiovascular or body composition fitness has not been established. On the other hand, with

one exception, which is noted in the following text, the studies reviewed have not shown that

high levels of any of these fitness components are in any way linked as causal factors to LBP.

Therefore, it appears prudent at this point to continue recommending a specific program of

truncal muscular fitness as a part of a comprehensive physical fitness activity program. This

recommendation is in accordance with the Healthy People 2000 goal, which states the aim of

increasing to at least 40% the proportion of the population six years old and above who

regularly perform physical activities that enhance and maintain muscular strength, muscular

endurance, and flexibility (Public Health Service, 1990). A comprehensive program would, of

course, utilize the entire body and, along with the trunk region, stress upper arm and shoulder

girdle areas. While baseline data suggest that the goal is close to being met for high school

students, for the total population the 1991 estimate is that only 16% are involved in such

programs.
For the trunk and low back region, it is imperative that the neuromuscular program go

beyond traditional sit-ups for abdominal strength (actually, partial curls should be substituted

for sit-ups) and modified hurdler’s stretches for hamstring flexibility. The exercise program

should be designed to include all five major anatomical areas and abilities listed in Table 13.1

without overemphasizing lumbar flexibility. Ignoring any element in the whole may lead to

imbalances. Table 13.1 presents suggested flexibility and muscular strength/endurance

exercises for the five identified areas with a progression from relatively easy to reasonably

hard. Individual selections can be made from this chart for each area. Even if these

components have not been shown irrevocably to be protective against the development of

LBP, truncal muscular strength, endurance, and flexibility are important aspects of a healthy,

fully functioning, fit body.

It should be noted that the activities listed in Table 13.1 are limited to those that require

no specialized equipment, not even free weights. They may, thus, be less than the optimal

exercise. For example, evidence is accumulating that back extensor exercises done on a

specialized machine (the MedXTM) that stabilizes the pelvis provides the best results. Without

pelvic stabilization, back extension strength may not be developed (Foster & Fulton, 1991;

Risch et al., 1993).

TA BLE 1 3 .1

SU GGES TED EXER CISE S FO R VA RIOU S FI TNES S LE VELS .

NE UROM USCU LAR FI TNES S COMP ONEN TS

a. Lu mbar mob ilit y*

b. Ha mstr ing flex ibil ity*

c. Hi p fl exor fle xibi lity *

d. Ab domi nal stre ngth /end uran ce** 

e. Ba ck e xten sor stre ngth /end uran ce** 

LO W

Kn ee t o Ch est

In supine lying position bring one or both knees to the chest, grasping the leg, under the thigh(s), raise and lower

head slowly.

Mo difi ed H urdl er’s Str etch 

Si t wi th o ne l eg s trai ght, the oth er f lexe d. M ove the flex ed k nee to t he s ide and bend for ward .

Hi p Ex tens ion

St and with pel vis in n eutr al p osit ion. Ext end leg back ward at hip. 

Pe lvic Til t

In sup ine lyin g or sta ndin g po siti on—p ress pel vis to f loor or wall .
Hy pere xten sion —1

Ly ing in p rone pos itio n wi th h ands at thig hs. Keep nec k an d ch in i n ne utra l po siti on and raise shoulders off

fl oor. 

MO DERA TE

“M ad C at”

Kneeling on all fours alternate head up with sway back and head tucked with rounded back.

PN F Su pine Pos itio n

Pl ace jump rop e ar ound foo t or ank le w ith leg rais ed a s st raig ht a s po ssi- ble . Co ntra ct a gain st r ope, rel ax,

an d pu ll l eg s trai ghte r. R epea t.

Ly ing Stre tch

Li e on tab le w ith knee s ov er t he e dge and back fla t. P ulli ng o ne l eg t o th e ch est (han ds o n th igh) str etch es

th e op posi te h ip.

Pa rtia l Cu rl ( crun ch)

Ho ok l ying pos itio n, f eet not held , ti lt p elvi s, c url up, slid ing hand s at sid e 3– 41/2 i nche s.

Hy pere xten sion —2

Ly ing in p rone pos itio n wi th a rms and hand s ex tend ed f orwa rd. Keep nec k an d ch in i n ne utra l po siti on a nd

ra ise shou lder s of f fl oor. 

HI GH

Cr osse d Le g Fl exio n

Si ttin g po siti on w ith knee s fl exed and ank les cros sed. Slo wly bend for ward unt il h ead appr oach es f loor .

St andi ng S tret ch

St and with one leg pla ced on a sup port at abou t 90 ° hi p fl exio n. K eepi ng b ack stra ight wit h sh ould ers

ba ck, flex for ward .

St andi ng S tret ch

St and in f orwa rd b ackw ard stri de p osit ion. Ben d fr ont knee and thr ust back hip for ward . Ke ep f ront kne e

ov er a nkle .

Ob liqu e Cu rl

Ly ing on s ide — tw ist trun k an d cu rl u p re achi ng f or t op l eg w ith oppo site arm .

Hy pere xten sion —3

Lying in prone position on a table or bench with body supported and stabilized from top of pelvis down. Flex

waist to 90° and extend to several inches above level.
TH E PR OBLE M

The incidence of low back pain has been and continues to be consistently high. At some time

in their lives, 60–80% of all individuals experience back pain. Both sexes are affected

equally. Most cases occur between the ages of 25 and 60 years, but no age is completely

immune. Fortunately, most LBP is acute and, with or without treatment of any kind, resolves

itself within three days to six weeks. After six weeks to a year, the condition is considered to

be chronic. For the 1–5% so afflicted, the condition is disabling. This statistic speaks directly

to the Healthy People 2000 priority of reducing disability from chronic disease, for while

LBP is not the most prevalent disabling disease in the U.S., it is one of the many (Public

Health Service, 1990). The psychological, social, and physical costs to individuals cannot

begin to be calculated. The medical, insurance, and business/industry costs have been

estimated into the billions of dollars per year (Cailliet, 1988; Plowman, 1992; Kumar, 1994).

Most cases of acute LBP arise spontaneously from no known cause. Without knowing the

exact cause or causes of LBP, it is difficult to determine risk factors that might predispose an

individual to LBP. Among the possible risk factors most commonly linked with LBP is a lack

of physical fitness. Indeed, LBP has often been labeled as a hypokinetic disease, that is, as a

disease caused by and/or associated with a lack of exercise (Kraus and Raab, 1961).

TH E TH EORE TICA L LI NK B ETWE EN P HYSI CAL

AC TIVI TY, PHYS ICAL FIT NESS , AN D LO W BA CK P AIN

The theoretical link between physical activity, physical fitness, and LBP is largely based on

functional anatomy Anatomically, back pain is primarily located in the lumbosacral region of

the back, which normally forms a lordotic curve. Twenty-four vertebrae comprise the entire

spine. Effective functioning of the back requires coordination of all of the vertebra, the pelvis,

the hip and thigh joints, and the muscles, fascia, and ligaments which originate and insert on

these bones. Such coordination is task-specific, but to be normal it should be completed with

minimal and equalized stresses within the spine (Cailliet, 1988; Gracovetsky, 1990).

Table 13.2 presents the theoretical relationships between all of the components of healthrelated physical fitness and healthy and unhealthy functioning of the low back. It can be seen

that there is a strong anatomical rationale for all components of fitness. The actual researchbased support is not as strong as the anatomical relationships.
TH E RE SEAR CH L INK BETW EEN PHYS ICAL ACT IVIT Y,

PH YSIC AL F ITNE SS, AND LOW BACK PAI N

Ty p es of re sea r ch st u d ie s. Studies that have attempted to determine the relationship

between physical activity and/or fitness and low back function or pain/injury are of two

primary types. The first are retrospective studies. In a retrospective study, the relationship

between the activity or fitness component and LBP is examined, or an attempt is made to

distinguish between those who do and do not have low back pain based on the activity or

fitness score. Retrospective studies must be interpreted cautiously since there are at least three

possible confounding problems. First, activity or fitness measures in individuals already

suffering from LBP may represent less than maximal effort due to real or feared pain.

Second, physical activity is generally spontaneously decreased in individuals suffering from

LBP, with the result that scores may reflect detraining as much as LBP per se. Third, these

studies statistically establish just relationships (some of which may be statistically significant

but not practically meaningful) and not cause and effect.

The second type of study is prospective. Prospective studies are longitudinal studies that

test either normal individuals with no history of LBP, individuals with a history of LBP, or

both, and then wait a specified time to see who develops LBP. The initial activity or fitness

variables are then statistically analyzed to determine which, if any, had the most predictive

value for the development of LBP. Prospective studies are obviously more valuable but they

are also harder to conduct.

Throughout this section it has been emphasized that either physical activity or physical

fitness can be used to determine the linkage with low back health or pain. In point of fact,

very few studies have even attempted to relate physical activity per se in nonathletic

populations with LBP. Those that have examined activity are weak in design and

contradictory in outcome, precluding any meaningful comments or conclusions. The biggest

difficulty is the inconsistent classification of physical activity and a primary reliance on

frequency of participation to the exclusion of duration and intensity (Plowman, 1992). Even

the most direct study by Porter, Adams, and Hutton (1989), which found a significant positive

relation between spinal motion segment compressive strength and physical activity in young

men killed in motorcycle accidents, relied only on a sports history obtained from the next of

kin.

A more recent 10-year prospective study by Leino (1993) did attempt to classify activity

levels into an exercise activity score (EAS = duration 3 estimated energy expenditure for

light, moderate, or strenuous intensity), a strenuous activity score (SAS = 500 kcal day21 or

more), and a total activity score (travel to and from work, housework, and exercise). Back

morbidity was assessed by both subject symptoms and clinical examination. At baseline, none

of the physical activity scores was statistically related to low back problems. Males exhibited

greater stability in EAS and SAS than females. Prospectively, for the males but not the

females, the lower EAS and/or SAS scores at baseline and five years, the higher the low back

problems after 10 years. When adjusted for other lifestyle factors, the SAS rating was not as

consistently predictive as that of the EAS. Part of the difficulty in discerning the relationship

between physical activity and low back pain is that it may be U-shaped. That is, both no or

too little activity and extremely strenuous activity (either absolute or relative to an

individual’s capabilities) may predispose an individual to low back problems. Thus, no

exercise prescription guidelines specific for low back health can be documented from the

literature. This is a fertile area for research.
The rest of this report will concentrate on the linkage between physical fitness and low

back health or pain. Some specific studies will be mentioned for illustrative purposes, but the

primary emphasis will be on general consensus. For a more in-depth presentation of the

research literature, the reader is referred to Plowman (1992). Complete references are also

provided there.

CA RDIO VASC ULAR FIT NESS AND LBP 

As stated in Table 13.2, a properly functioning cardiovascular system is necessary for disc

nourishment and to slow disc degeneration. The exact relationship with total body

cardiovascular fitness has received little attention. Only two retrospective studies have

measured cardiovascular fitness, and neither established a definitive linkage with low back

function (Plowman, 1992).

Likewise, only two prospective studies have designs specific enough to draw conclusions

from, but unfortunately the conclusions that must be drawn are in opposition to each other.

The first study was completed on fire fighters by Cady, Thomas, and Karwasky (1985).

Cardiovascular condition was assessed by physical working capacity (PWC). The 20 fire

fighters with the lowest PWC incurred much higher low back injury costs than the 20 with the

highest PWC, showing a beneficial effect. The second study is the study with the stronger

design. It was conducted by Battié et al. (1989). Maximal oxygen consumption (VO2max)

was predicted from a submaximal treadmill test on over 2,400 Boeing airplane employees.

VO2max was not found to be predictive of the 228 back problems which occurred in these

employees over the subsequent four years.

Haliovaara et al. (1995) have presented epidemiological evidence against the theory that

atherosclerosis (the narrowing of blood vessels as a result of the build-up of plaque)

contributes to the development of LBP by determining death rates from cardiovascular

disease in individuals with and without LBP. Comprehensive health examinations were

performed on 7,217 individuals representative of the Finnish population. Seventy-six percent

had a history of LBP complaints; 17% were diagnosed with chronic LBP. Twelve to 14 years

later, 1,487 individuals had died from cardiovascular disease. Neither a history of LBP

complaints nor diagnosed chronic LBP predicted cardiovascular mortality.

There is no evidence that a highly fit cardiovascular system is detrimental in any way, but

the evidence of benefit is minimal. This is another area which requires further research.
BO DY C OMPO SITI ON A ND L BP

The skeletal system in general and the spine in particular are the primary supporting

structures of the body. As pointed out in Table 13.2, if the weight the spine supports is

largely muscular and the muscles are both strong and flexible, healthy functioning should

result. However, if a large portion of the body mass is fat, this adds excess weight and pressure

on the discs without any positive assistance. The few studies which have utilized body mass

index (WT/HT2) (BMI) and/or skinfolds as an indication of body composition have shown

split results. However, an analysis of the NHANES-II national probability sample data set did

show a substantial increase in LBP prevalence (1.7 times higher) in the most obese 20%

compared with the least obese 20% of the 10,404 adult subjects when obesity was defined by

both BMI and skinfold measures. No studies have been done on LBP in which body

composition has been directly assessed by a laboratory criterion measure such as underwater

weighing (Plowman, 1992).

NE UROM USCU LAR FITN ESS AND LBP

The most important components of fitness in relation to healthy functioning of the low back

are muscular strength, muscular endurance, and flexibility. It is necessary that each separate

muscle group possess both strength/endurance and flexibility, and that anatomically opposing

muscle groups are balanced in strength/endurance and flexibility. The goal in relation to the

low back region is that the vertebra will be kept in proper alignment without excessive disc

pressure throughout the full range of possible motions. In addition, the pelvis must freely

rotate both posteriorly and anteriorly without strain on the muscles or fascia. Table 13.2

presents the specific actions of the back, hip, abdominal, and hamstring muscles and what can

theoretically happen if these muscles are allowed to become weak, easily fatigued, and/or

inflexible.

The research evidence shows that regardless of the testing mode (that is, whether the test is

one of static or dynamic function), individuals with low back pain exhibit lower strength

values of both the abdominals and back extensor groups than do individuals without LBP.

Only two studies looked at trunk extensor endurance specifically, but both of these found that

individuals with LBP severe enough to limit function had scores lower than those without such

limitations (Plowman, 1992).

Perhaps the most interesting studies in this area are those utilizing electromyographic

(EMG) analysis of back extensor fatigue. In each of the three studies (DeVries, 1968, Roy,

DeLuca, & Casavant, 1989; Roy et al., 1990), 80–100% of those with LBP showed increased

electrical activity during sustained static muscle contraction. While these were not intended to

be prospective studies, in one case an individual who showed high EMG activity but no

history of LBP developed LBP the following year. Retrospective studies of low back pain and

hamstring flexibility have shown the same trend. That is, there is a significant relationship

between tightness in those muscle groups and LBP (Plowman, 1992).
Prospective studies of neuromuscular fitness are neither as numerous nor as definitive as

the retrospective ones. Only one strength/endurance study found any variable predictive of

first-time low back pain, and this showed the predictive variable to be limited (low) back

extensor endurance (Biering-Sorensen, 1984a). Unfortunately, this was the only study using

this variable, but since it is consistent with the results of the retrospective studies it would seem

that back extensor endurance needs to be given more attention. Recurrent back pain has been

successfully predicted in about half of the studies of trunk and back extensor

strength/endurance with, as expected, low scores preceding the reoccurrence of back pain

(Plowman, 1992).

One prospective study found lumbar flexibility to be predictive of first-time LBP

(Biering-Sorensen, 1984b). In it, increased (not decreased as might be expected) lumbar

mobility was found to be predictive of first-time back pain in males but not females. It is

anatomically possible that extreme lumbosacral flexion stresses the discs at that site (Sharpe,

Liehmon, & Snodgrass, 1988). Recurrent back pain has been found to be predictable from

both low lumbar extension range of motion and low hamstring flexibility.

No specific level of strength, endurance and/or flexibility has emerged as critical in any of

these studies. Hopefully, further research to clarify these issues will be forthcoming.

Part of the difficulty in experimentally being able to provide evidence concerning the

relationship of lumbar extension and flexion strength, endurance, and flexibility and low

back pain may be in the previously available equipment. Specifically, testing of the lumbar

extensor muscles without stabilization of the pelvis may have led to inaccurate results and

conclusions. If the pelvis moves during testing, the force measured also includes some

unknown contribution from the hip extensors and is not truly a measure of back extension

strength (Jones, 1993).

CH ILDR EN / AD OLES CENT S AN D LB P

Historically, LBP in adolescents and especially children was considered indicative of a serious

pathological condition, either anatomical or physiological (King, 1986). Statements such as

“backache is so rare in the prepubertal and early pubertal patient that such patients should

undergo a complete work-up for a serious cause....” (Dymet, 1991, p. 170) were

commonplace. Today, however, evidence is mounting that LBP is no longer rare in this age

group. Over half a dozen large sample studies of Scandinavian and European children in the

past decade (Balague, Dutoit, & Waldburger, 1988; Balague et al., 1993; Burton et al., 1996;

Mierau, Cassidy, & Yong-Hing, 1989; Salminen, Pentti, & Terho, 1992; Taimela et al., 1997;

Troussier et al., 1994) have shown that the incidence of LBP is relatively low prior to puberty

(1–28%) but falls very close (50–80%) to the adult range by the early- to mid-teen years.

Some studies report that young females have more LBP than young males, but the role of

back discomfort associated with the menstrual cycle does not appear to have been clarified in

these studies.

The relationship between physical activity and LBP in children and adolescents suffers

from the same ambiguities as for adults. In most studies, youngsters both with and without

LBP have been evenly distributed into low, moderate, and high activity groups (Balague et al.,

1993; Kujala et al., 1992; Salminen, 1984; Taimela et al., 1997; Troussier et al., 1994). In one

study (Salminen et al., 1995) low participation in activity was associated with increased

frequency of LBP. However, in still others, high participation, especially in heavy sports

training, has been associated with an increased incidence of LBP (Balague, Dutoit, &

Waldburger, 1988; Burton et al., 1996; Kujala et al., 1992; Taimela et al., 1997).
Cardiovascular fitness has not been investigated in relation to LBP in this age range, but

several attempts have been made to relate anthropometric variables to LBP. Neither height,

weight, nor body mass index (BMI) has been shown to be predictive of future LBP (Salminen

et al., 1993; Salminen et al., 1995). However, a tall sitting height and a high degree of

asymmetry as measured by the forward bending test may play a modest role in LBP

(Fairbank et al., 1984; Nissinen et al., 1994).

Isokinetic trunk flexion and extension strength were found to be no different between 10-

and 16-year-olds with and without LBP (Balague et al., 1993); however, both abdominal and

back extensor muscular endurance did differ significantly between youngsters with and

without LBP (Salminen et al., 1993). These muscular endurance measures, however, were not

predictive of LBP in a three-year follow-up study (Salminen et al., 1995).

Flexibility measures have been shown to be positively, negatively, and nonsignificantly

related to LBP (Burton et al., 1989; Burton et al., 1996). A positive relationship means that a

high degree of mobility is associated with LBP. High lumbar mobility was apparent in

children and adolescents with LBP but, unlike the Biering-Sorensen (1984a) results in adults,

was not found to be predictive of LBP in youngsters (Salminen et al., 1993; Salminen et al.,

1995). Decreased hamstring flexibility (Mierau, Cassidy, & Yong-Hing, 1989; Salminen et al.,

1993; Salminen et al., 1995), decreased femoral and tibial rotation (Fairbank et al., 1984),

and decreased lumbar extension and flexion (Salminen et al., 1993; Salminen et al., 1995)

have all been associated with increased LBP in children and adolescents, but no evidence

exists that any of these can predict future LBP.

Thus, the pattern of the relationship between physical activity and/or physical fitness variables

is no clearer in children and adolescents than in adults. It does seem that LBP is more of a

problem in children and adolescents than previously thought. However, for individuals of

all ages the key may be in the degree of the predisposing factors, not just whether an

individual is active, strong, or flexible. Continued investigation into factors predictive of

LBP in children and adolescents is important to try to avoid LBP at this age, but it is also

important because a better understanding of LBP in children and adolescents may yield

clues to the origins of adult LBP and to a means of prevention. In the meantime,

moderate levels of activity are to be encouraged for all since, at the very least, this level of

activity appears to do no harm to the back.

R EF ER EN CE S

Balague, F., Damidot, P., Nordin, M., Parnianpour, M., & Waldburger, M. (1993). Cross-sectional study of the

isokinetic muscle trunk strength among school children. Spine, 18, 1199–1205.

Balague, F., Dutoit, G., & Waldburger, M. (1988). Low back pain in school children: An epidemiological study.

Scandinavian Journal of Rehabilitative Medicine, 20, 175–179.

Battié, M.C., Bigos, S.J., Fisher, L.D., Hansson, T.H., Nachemson, A.L., Spengler, D.M., Wortley, M.D., &

Zeh, J. (1989). A prospective study of the role of cardiovascular risk factors and fitness in industrial back pain

complaints. Spine, 12, 141–147.

Biering-Sorensen, F. (1984a). A one-year prospective study of low back trouble in a general population. Danish

Medical Bulletin, 31, 362–375.

Biering-Sorensen, F. (1984b). Physical measurements as risk indicators for low-back trouble over a one-year

period. Spine, 9, 106–119.

Burton, A.K., Clarke, R.D., McClune, T.D., & Tillotson, K.M. (1996). The natural history of low back pain in

adolescents. Spine, 21, 2323–2328.

Burton, A.K., Tillotson, K.M., & Troup, J.D.G. (1989). Variation in lumbar sagittal mobility with low-back

trouble. Spine, 14, 584–590.
Cady, L.D., Thomas, P.C., & Karwasky, R.J. (1985). Program for increasing health and physical fitness for fire

fighters. Journal of Occupational Medicine, 27, 110–114.

Cailliet, R. (1988). Low back pain syndrome, 4th edition. Philadelphia: F.A. Davis.

DeVries, H.A. (1968). EMG fatigue curves in postural muscles. A possible etiology for idiopathic low back pain.

American Journal of Physical Medicine, 47, 175–181.

Deyo, R.A., & Bass, J.E. (1989). Lifestyle and low-back pain: The influence of smoking and obesity. Spine, 14,

501–506.

Dymet, P.G. (1991). Low back pain in adolescents. Pediatric Annals, 20, 170–178.

Fairbank, J.C.T., Pynsent, P.B., van Poortvliet, J.A., & Phillips, H. (1984). Influence of anthropometric factors

and joint laxity in the incidence of adolescent pain. Spine, 9, 461–464.

Foster, D.N., & Fulton, M.N. (1991). Back pain and the exercise prescription. Clinics in Sports Medicine, 10,

197–209.

Gracovetsky, S., Kary, M., Levy, S., Ben Said, R., Pitchen, I., & Helie, J. (1990). Analysis of spinal and

muscular activity during flexion/extension and free lifts. Spine, 15, 1333–1339.

Heliovaara, M., Makela, M., Aromaa, A., Impivaara, O., Knekt, P., & Reunanen, A. (1995). Low back pain and

subsequent cardiovascular mortality. Spine, 20, 2109–2111.

Jones, A. (1993). The lumbar spine, the cervical spine and the knee: Testing and rehabilitation. Ocala, FL: MedX

Corporation.

King, H.A. (1986). Evaluating the child with back pain. The Pediatric Clinics of North America, 33, 1489–1493.

Kraus, H., & Raab, W. (1961). Hypokinetic disease. Springfield, IL: Charles C. Thomas.

Kujala, U.M., Salminen, J.J., Taimela, S., Oksanen, A., & Jaakkola, L. (1992). Subject characteristics and low

back pain in young athletes and nonathletes. Medicine and Science in Sports and Exercise, 24, 627–632.

Kumar, S. (1994). The epidemiology and functional evaluation of low-back pain: A literature review. Physical

Medicine and Rehabilitation, 4, 15–27.

Leino, P.I. (1993). Does leisure time physical activity prevent low back disorders? A prospective study of metal

industry employees. Spine, 18, 863–871.

Mierau, D., Cassidy, J.D., & Yong-Hing, K. (1989). Low-back pain and straight leg raising in children and

adolescents. Spine, 14, 526–528.

Nissinen, M., Heliovaara, M., Seitsamo, J., Alaranta, H., & Poussa, M. (1994). Anthropometric measurements

and the incidence of low back pain in a cohort of pubertal children. Spine, 19, 1367–1370.

Plowman, S.A. (1992). Physical activity, physical fitness, and low back pain. In J.O. Holloszy (Ed.), Exercise

and Sport Sciences Review, 20, 221–242.

Porter, R.W., Adams, M.A., & Hutton, W.C. (1989). Physical activity and the strength of the lumbar spine.

Spine, 14, 201–203.

Public Health Service. (1990). Healthy People 2000. Washington, D.C.: U.S. Government Printing Office.

Risch, S.V., Norvell, N.K., Pollock, M.L., Risch, E.D., Langer, H., Fulton, M., Graves, J.E., & Leggett, S.H.

(1993). Lumbar strengthening in chronic low back pain patients: Physiologic and psychological benefits.

Spine, 18, 232–238.

Roy, S.H., DeLuca, C.J., & Casavant, D.A. (1989). Lumbar muscle fatigue and chronic lower back pain. Spine,

14, 992–1001.

Roy, S.H., DeLuca, C.J., Snyder-Mackler, L., Emley, M.S., Crenshaw, R.L., & Lyons, J.P. (1990). Fatigue,

recovery, and low back pain in varsity rowers. Medicine and Science in Sports and Exercise, 22, 463–469.

Salminen, J.J. (1984). The adolescent back: A field survey of 370 Finnish schoolchildren. Acta Paediatrica

Scandinavica, Supplement 315, 8–122.

Salminen, J.J. (1992). Spinal mobility and trunk muscle strength in 15-year-old schoolchildren with and without

low-back pain. Spine, 17, 405–411.

Salminen, J.J. (1995). Low back pain in the young. Spine, 19, 2101–2108.

Salminen, J.J., Oksanen, A., Maki, P., Pentti, J., & Kujala, U.M. (1993). Leisure time physical activity in the

young: Correlation with low-back pain, spinal mobility and trunk muscle strength in 15-year-old school

children. International Journal of Sports Medicine, 14, 406–410.

Salminen, J.J., Pentti, J., & Terho, P. (1992). Low back pain and disability in 14-year-old schoolchildren. Acta

Paediatrica, 81, 1035–1039.
Sharpe, G.L., Liehman, W.P., & Snodgrass, L.B. (1988). Exercise prescription and the low back-kinesiological

factors. Journal of Health, Physical Education, Recreation and Dance, 59(8), 74–78.

Taimela, S., Kujala, U.M., Salminen, J.J., & Viljanen, T. (1997). The prevalence of low back pain among

children and adolescents: A nationwide, cohort-based questionnaire survey in Finland. Spine, 22, 1132–1136.

Troussier, B., Davoine, P., deGaudemaris, R., Fauconnier, J., & Phelip, X. (1994). Back pain in school children:

A study among 1178 pupils. Scandinavian Journal of Rehabilitative Medicine, 26, 143–146.