Trunk-Strengthening Exercises for Chronic Low Back Pain: A Systematic Review

LITERATURE REVIEW

TRUNK-STRENGTHENING EXERCISES FOR CHRONIC LOW

BACK PAIN: A SYSTEMATIC REVIEW

Susan C. Slade, M Manip Ther, PT,a and Jennifer L. Keating, PhD, PTb

ABSTRACT

a PhD CandidatSciences, La Trob

b Professor, HeaCare, Faculty of MUniversity, MelboSources of supp

work.Submit requests

Box Hill, Victoria(e-mail: elgarphysPaper submitted0161-4754/$32.Copyright D 20doi:10.1016/j.jm

Objective: The objective of this systematic review was to determine the effect of lumbar spine-strengthening exercises

on outcomes for people with chronic low back pain.

Methods: Two independent reviewers followed Cochrane Back Review Group and QUORUM Statement guidelines to

complete this systematic review. Exercise effects were reported as standardized mean difference (SMD) with 95%

confidence intervals.

Results: Thirteen high-quality randomized controlled trials were included. For chronic low back pain, trunk

strengthening is more effective than no exercise on long-term pain (SMD 0.95 [0.35-1.55]; intensive trunk strengthening is

more effective than less intensive on function (pooled SMD: short-term, 0.58 [0.22-0.94]; long-term, 0.77 [0.33-1.20]).

Compared with physiotherapy or aerobics, effects are comparable on pain and function. Motivation strategies increase

effectiveness. After disk surgery, effects are significant for function (pooled SMD: short-term, 1.08 (0.76-1.41); long-term,

0.53 (0.03-1.04). For severe degeneration, trunk strengthening is less favorable than fusion on long-term pain (SMD,

�0.50 [�0.99 to �0.01]) or function (SMD, �0.76 [�1.25 to �0.26]). Intensive trunk strengthening is less effective than

McKenzie exercises for pain reduction (SMD: short-term, �0.29 [�0.54 to �0.05]; long-term, �0.31 [�0.55 to �0.06]).

We estimated that moderate effect sizes (0.5) indicate that approximately 50% of participants and large effect sizes (0.8)

indicate that approximately 80% of participants would achieve important improvement.

Conclusions: Trunk strengthening appears effective compared with no exercise. Increasing exercise intensity and

adding motivation increase treatment effects. Trunk strengthening, compared with aerobics or McKenzie exercises,

showed no clear benefit of strengthening. It is unclear whether observed benefits are due to tissue loading or movement

repetition. (J Manipulative Physiol Ther 2006;29:163-173)

Key Indexing Terms: Low Back Pain; Exercise Therapy; Review, Systematic; Outcome Assessment (Health Care)

Historically, low back pain (LBP) has been consid-

ered self-limiting, but the results of prospective

trials indicate that although acute symptoms

resolve in 1 to 2 months, they usually recur intermittently

in most patients. People reporting chronic low back pain

(CLBP) may have continuation of an initial episode or

e, School of Physiotherapy, Faculty of Healthe University, Melbourne, Australia.d of Physiotherapy, School of Primary Healthedicine, Nursing and Health Sciences, Monashurne, Australia.ort: No funds were received in support of this

for reprints to: Susan Slade, P.O. Box 1241,, Australia [email protected]).March 30, 2005.0006 by National University of Health Sciences.pt.2005.12.011

periodic recurrences and remissions. Once chronic, the

condition is associated with long-term disability and work

absence.1,2

Cochrane reviews have concluded that exercise appears

beneficial for people with CLBP,3 enhances disk surgery

outcomes,4 and assists return to daily activities and work.5

The type of exercise tested for these recommendations

typically includes combinations of stretching, strengthening,

and unloaded movement exercises. Review outcomes do

not assist clinicians in designing exercise programs. It is

not clear how exercise effects are mediated by exercise

type, by program length, exercise intensity, session dura-

tion, supervision or motivational factors, or by home

practice. The former lists only some of the challenges

facing health care providers wishing to write sensible exer-

cise prescriptions.

At present, clinicians are not able to advise their pa-

tients about the probability of success under specified

exercise programs. The optimal type of exercise for

163

164 Journal of Manipulative and Physiological TherapeuticsSlade et al

February 2006Trunk Strengthening Exercises

CLBP is not known because the effects of specific

exercises have not been systematically assessed. Given

the common recommendation for trunk-strengthening

exercises, this review sought to identify the effects of

trunk-strengthening exercises, compared with other or no

treatments, to quantify the likely benefits for people with

CLBP and to determine the proportion of people with

CLBP likely to benefit by an important amount. It was

predicted that the review outcomes would allow health

care providers to advise their patients about expected

benefits associated with trunk-strengthening programs. We

conducted a systematic review to determine the magnitude

of effects attributable to trunk strengthening on pain or

function for people with CLBP (with and without surgery)

and to describe these programs.

METHODS

Inclusion CriteriaRandomized controlled trials (RCTs), published in peer-

reviewed journals, with method scores of 6 of 10 or greater

on a modified Physiotherapy Evidence Database (PEDro)

quality assessment scale were included.6 Participants had

to be at least 16 years old, with a current LBP episode of

8 weeks or more, with or without a history of back surgery.

The decision regarding LBP duration was made to capture

the largest number of studies of exercise for CLBP that

included the least number of participants likely to show

natural recovery during the intervention period.2 As few as

10% with LBP at 8 weeks are recovered at 12 months.1 We

defined LBP following the example of van Tulder et al 3 as

pain below the scapulae and above the buttock fold, with

or without lower extremity radiation. Interventions had to

be exercises intended to strengthen or load muscles acting

over the lumbar spine with or without warm-up and

stretching exercises. If there were therapy combinations,

studies were included if exercise effects could be partitioned

from other intervention effects. Outcomes had to be at least

one of functional capacity, pain, work status, or satisfaction

with treatment.

Exclusion CriteriaExcluded were non-English publications because trans-

lation funding was unavailable and studies of participants

with conditions not typically treated by trunk-strengthening

exercises: neoplasm, inflammatory arthritis, multiple scle-

rosis, osteoporosis, and pregnancy.

Study Identification and SelectionElectronic databases were searched without date limits

until February 2004, using explosions of key search terms

for back pain and exercise. Search strategies followed

Cochrane Collaboration recommendations and are available

from the first author.7 Databases searched were MEDLINE,

EMBASE, CINAHL, Cochrane Database of Systematic

Reviews, Cochrane Central Register of Controlled Trials,

PEDro, Current Contents, Expanded Academic, Australian

Medical Index, and SportDiscus. Relevant systematic

reviews and reference lists of included papers were

screened, 11 key journals were hand-searched, content

experts were consulted, and relevant work was sought by

citation tracking.

Method Quality AssessmentMethod quality of each RCT was assessed by two

independent reviewers using a 10-item checklist based on

the PEDro scale,6 and disagreement was resolved by

discussion. It is not possible or desirable to blind therapists

to the fact that they are administering exercises. We replaced

this PEDro criterion with bwere cointerventions avoided or

equal?Q to assess the likelihood that observed effects were

genuinely attributable to the exercise programs.7

Data ExtractionData relevant to the review aims were systematically

extracted by two independent reviewers with disagreement

resolved by discussion.7 Six authors were contacted for

additional information. To assess treatment effects, data

were extracted for relevant outcomes at baseline, end of

intervention, and at follow-up assessments.

Data AnalysisThe effect of trunk-strengthening exercise for CLBP,

compared with alternative or no treatment, was estimated

using Hedges bias-corrected effect size (ES) index.8-10

Effect size is also referred to as standardized mean differ-

ence (SMD)11 and is the mean outcome difference between

intervention and comparison groups divided by the post-

intervention control group standard deviation (SD).12,13 It

provides a common metric for reporting effects across a

range of outcome measurements. Calculations were adjusted

so that positive SMDs always indicated better outcomes for

trunk strengthening.11 By convention, an SMD of 0.8

indicates large intervention effects; 0.5, a moderate effect;

and 0.2, a small effect.9 A 95% confidence interval (CI)

around the SMD was calculated for an estimate of the range

of intervention effects. Standardized mean difference may

be translated into clinically relevant values on a 0-to-100

scale for pain and function. For pain, a moderate ES of

0.5 equates to a mean reduction of pain in the order of 12 of

100 points and of function in the order of 9 of 100 points.

Norman et al14 observed that a change of half an SD is

typically found to represent a clinically important change in

scores. Hence, if an ES of 0.5 is identified, a clinically

important score difference occurred for 50% of those in the

intervention group.

Fig 1. Progress through the stages of RCT selection for systematic review.

Slade et alJournal of Manipulative and Physiological Therapeutics

Trunk Strengthening ExercisesVolume 29, Number 2165

When unavailable, the SD was estimated by the average

SD (weighted by sample size) of scores for comparable

measures in other included studies. For pain and function

scores, this was estimated as 23.6% and 18.5%, respec-

tively.15 When necessary, SD was estimated using one

fourth of the 10 to 90 percentile score16 or converted from

the standard error in the estimate of the mean (SEM) or an

appropriate 95% CI. Median scores were entered into SMD

calculations as best estimates of mean scores. Where

sensible, data were pooled to provide an overall effect

estimate. Meta-analyses using random effects modeling

were performed using Cochrane Collaboration Review

Manager 4.3.2 software, which is used for the preparation

and maintenance of Cochrane Reviews. It was developed by

the Nordic Cochrane Centre and is available from the

Cochrane Library.7,11

RESULTS

Study Identification and SelectionThe search yield of 4880 references was sorted by title

and abstract, and 4625 were clearly unsuitable. Two inde-

pendent reviewers examined the remaining 265 papers,

discarded 180 papers on title and abstract, and read 85 papers

in detail. Inclusion and exclusion criteria were applied, and

15 trials17-31 appeared to satisfy the criteria (Fig. 1). Details

of excluded trials are available from the first author.



Of the 15 potentially appropriate papers, 2 were rejected

because method quality was below 6 of 10. Included papers

had a mean method quality score of 6.8 of 10. For all

but 2 reports,17,31 method assessments had been completed

by 2 independent PEDro reviewers. There was consen-

sus across the 4 reviewers for 9 items common to the

original and modified PEDro scales. All studies randomly

allocated participants to groups, provided outcomes with

comparable baseline measures, appeared to avoid confound-

ing cointerventions, and provided data for intervention

effect estimates.

Exercise ProgramsAppendix Table 1 summarizes intervention and compar-

ison categories. In 4 programs classified by authors as

intensive,21,23,24,27 participants performed a minimum of

50 repetitions of each exercise during each intervention

session and were considered separately.

Interventions and comparison components are summar-

ized in Appendix Table 2, and 6 trials21,23,24,27,30,31 provided

explicit descriptions. The number of times each exercise was

performed was reported for 4 comparison groups23,24,30,31

and 9 intervention groups.17,18,21,23-25,27,30,31 The number of

dropouts was reported for 7 trials,17,21-25,27 and adverse

effects were reported for 5 trials.21,23,24,26,27 Three trials

measured return to work,17,20,27 and 4 trials, patient

satisfaction.23,24,26,27 Recurrence rates were not reported.

Data AnalysisStandardized mean difference calculations were per-

formed using SD derived from 95% CI around the

SEM,18,26 SEM,19 range scores,17 and 10 to 90 percen-

tiles23,24,27 for pain and function. The weighted average

SD was used for 1 trial,21 and intention-to-treat data

were used for 4 trials.18,21,25,27 Standardized mean differ-

ence was calculated using the postintervention median

scores,17,21,24,27 differences in median,23 or mean25 change

scores and could not be calculated for comparisons with

no reported sample sizes.23 For 5 reports,17,23,25,30,31

outcomes for the trunk-strengthening group were com-

pared with several therapies. The differences in observed

effects may not satisfy the statistical assumption of

independence required for meta-analysis, so sample size

of the trunk-strengthening group used to calculate

SMD for each comparison was divided by the number

of comparisons.37

Standardized Mean DifferenceProgram effects (SMD with 95% CI) on pain and

function are summarized in Appendix Table 3. Effect sizes

were pooled in meta-analysis for a few studies with

comparable interventions.10-12,18,19,21,23,30,31,38

Chronic Low Back Pain Without SurgeryOne trial of trunk strengthening compared with no

exercise indicated small, insignificant, short-term effects

and large, significant, long-term effects for pain and

inconclusive effects for function.22 One trial with motivation

strategies applied to the intervention program indicated

large, significant effects for long-term pain and moderate,

insignificant effects for function.20 Trunk strengthening

compared with general exercise, physical therapy, or

aerobics indicated small, insignificant pooled effects.24,25

Intensive trunk strengthening compared with coordination

training and less intensive or isometric exercise indicated

significant pooled effects: moderate for short-term and large

for long-term function.21,23 Intensive trunk strengthening

compared with the McKenzie approach was not pooled

because it was not comparable with the other interventions.27

Chronic Low Back Pain With Surgical HistoryFor CLBP after surgery other than fusion, pooled effects

of trunk-strengthening exercise compared with no exercise

were large and significant for short-term pain and func-

tion,18,19,30,31 moderate and significant for long-term

pain,18,19 and moderate and insignificant for long-term

function.18,19 Compared with other exercises, pooled effects

indicated moderate insignificant effects for short-term

function.30,31 After discectomy, the effects for short-term

function were large and significant for active lumbar

extension exercise compared with active hyperextension.23

After lumbar fusion, trunk-strengthening effects compared

with behavioral therapy or video-based home exercises

were small and inconclusive for short- and long-term pain.17

For severe degeneration or spondylolisthesis, the long-term

effects favored fusion surgery compared with strengthening

exercise: moderate for pain and large for function.26

DISCUSSION

For CLBP without surgery, trunk strengthening com-

pared with no exercise produced moderate effects for long-

term pain and indicate benefit for long-term function.22

When trunk strengthening was compared with aerobics and

physical therapy with unspecified exercise, comparable

intervention and comparison group outcomes were

observed.24,25 This may be because exercise programs

encouraging movement are equally effective as those with

a strengthening focus or that strengthening challenges were

similar for comparison and intervention participants. The

addition of motivation strategies improved long-term pain

and function.20 Intensive exercise programs had large, short-

term effects on pain and large effects on function (short- and

long-term), compared with other treatments.21,23,27 One trial

comparing intensive training to the McKenzie approach39

indicated small significant effects on pain (short- and long-

term), favoring McKenzie.27



After disk surgery, there were large effects on short-term

pain and function, moderate effects on long-term pain, and

moderate, non significant, long-term effects on function

when compared with no exercise.18,19,30,31 Exercise without

active hyperextension had large, significant effects com-

pared with exercise with active hyperextension. Active

loading of the posterior spinal structures may disadvantage

this group.24 After lumbar fusion, trunk-strengthening

exercise compared with video-based home program had

small, non significant effects on short- and long-term pain.

Function was not measured.17

Norman et al14 reported that a change of a half SD across

health assessment scales typically indicates a change that

people consider important. Given our estimates of SDs for

pain and function of 23.6 of 100 and 18.5 of 100 points,

respectively, calculations based on the proposal of Norman

et al are aligned with reported estimates of minimal

clinically important differences. A 2-point difference on a

0 to 11 numeric pain scale40 (equivalent to 18.2 on a

100-point pain scale) and a 10- to 13-point difference on

a 0 to 100 Oswestry functional scale have been argued to

be clinically important.41,42 For many people with CLBP, a

change in function of this magnitude shifts limitation from

severe to moderate or moderate to minimal. Where moderate

ESs (0.5) were observed, we estimated that approximately

50% of participants performing trunk-strengthening exer-

cises would achieve significant benefit. Where large ESs

(0.8) were observed, we estimated that approximately 80%

of participants could expect substantial improvement (eg,

short-term pain,18,19,21,30,31 long-term pain,20,22,26,27 short-

term function,21,23 and long-term function21,23,27).

Incomplete program descriptions limit the confidence in

accurate replication of many interventions. It would advance

the science of exercise prescription to have details that

facilitate replication.

CONCLUSIONS

When compared with no exercise, trunk strengthening is

effective for reducing pain and improving function. Results

are promising for people with nonspecific CLBP and after

lumbar disk surgery. More intensive programs and those that

include motivational strategies appear to be of greater

benefit than less intensive programs. When less intensive

programs are compared with other types of exercise with

less apparent emphasis on strengthening, outcomes appear

similar. McKenzie exercises appear more beneficial than

strengthening programs for some people with CLBP.

People with severe degeneration or spondylolisthesis may

respond better to surgical fusion. Reports of trials of

exercise therapy should include explicit descriptions of

exercises and program design.

These conclusions are derived from individual studies or

meta-analysis of small numbers of comparisons. This review

identifies the likely benefit of trunk strengthening for CLBP

and after disk surgery. It is unclear whether benefits are a

consequence of muscle loading or movement repetition. The

effects of other types of exercise for people with CLBP can

now be compared with our results, and hypotheses about the

most effective types of exercise can be developed.

REFERENCES

1. Hestbaeck L, LeBoeuf-Yde C, Engberg M, Lauritzen T, BruunNH, Manniche C. The course of low back pain in a generalpopulation. Results from a 5-year prospective study. JManipulative Physiol Ther 2003;26:213-20.

2. Pengel LHM, Herbert RD, Maher CG, Refshauge KM. Acutelow back pain: systematic review of its prognosis. BMJ 2003;327:323.

3. van Tulder MW, Malmivaara A, Esmail R, Koes BW. Exercisetherapy for low back pain (Cochrane Review). The CochraneLibrary, Issue 3Chichester (UK)7 John Wiley & Sons, Ltd;2004. p. 1-26.

4. Ostello RWJG, deVet HCW, Waddell G, Kerckhoffs MR,Leffers P, van Tulder MW. Rehabilitation after lumbar discsurgery (Cochrane Review). The Cochrane Library, Issue 3.Chichester (UK)7 John Wiley & Sons, Ltd; 2004. p. 1-16.

5. Schonstein E, KennyDT, Keating J, Koes B.Work conditioning,work hardening and functional restoration for workers with backand neck pain (Cochrane Review). The Cochrane Library, Issue3. Chichester (UK)7 John Wiley & Sons, Ltd; 2004. p. 1-48.

6. Maher CG, Sherrington C, Herbert RD, Moseley AM,Elkins M. Reliability of the PEDro scale for rating methodo-logical quality of randomized controlled trials. Phys Ther 2003;83:713-27.

7. van Tulder M, Furlan A, Bombadier C, Bouter L. Updatedmethod guidelines for systematic reviews in the CochraneCollaboration Back Review Group. Spine 2003;28:1290-9.

8. Altman DG, Schulz KF, Moher D, Egger M, Davidoff F,Elbourne D. The Revised CONSORT Statement for reportingrandomized trials: explanation and elaboration. Ann InternMed 2001;134:663-84.

9. Cohen J. Statistical power analysis for the behaviouralsciences. Hillsdale (New Jersey)7 L. Erlbaum Associates; 1988.

10. Hedges L, Olkin I. Statistical methods for meta-analysis.USA7 Academic Press; 1985.

11. Cochrane Handbook. Alderson P, Green S, Higgins J, editors.Cochrane Reviewers’ Handbook 4.2.2 [updated March 2004];Section 8. The Cochrane Library, Issue 1. Chichester (UK)7John Wiley & Sons, Ltd; 2004. p. 68-139.

12. Glass GV. Primary, secondary, and meta-analysis of research.Educ Res 1976;5:3-8.

13. Glass GV, McGraw B, Smith ML. Meta-analysis in socialresearch. Chapter 5. Beverly Hills (Calif)7 Sage Publications;1981. p. 93-152.

14. Norman GR, Sloan JA, Wyrwich KW. Interpretation of changesin health-related quality of life: the remarkable universality ofhalf a standard deviation. Med Care 2003;41:582-92.

15. Herbert RD. How to estimate treatment effects from reports ofclinical trials. 1: continuous outcomes. Aust J Physiother 2000;46:229-35.

16. Ferreira ML, Ferreira PH, Latimer J, Herbert RD, Maher CG.Does spinal manipulative therapy help people with chronic lowback pain? Aust J Physiother 2002;48:277-84.

17. Christensen FB, Laurberg I, Bunger CE. The importance of theback-cafe concept to rehabilitation after lumbar spinal fusion: arandomized clinical study with a 2-year follow-up. Spine2003;28:2561-9.

APPENDIX

Table 1. Summary of programs for CLBP (and CLBP aftersurgery)

Trunk-strengthening exercise compared with:

Comparison Author

No exercise Kankaanpaa et al22

No exercise (after disk surgery) Danielsen et al18;

Dolan et al19;

Timm30; Yilmaz et al31

Strengthening + unloaded

flexion/extension movements

(after disk surgery)

Yilmaz et al31

Stabilization exercises combined

with McKenzie-type extension

exercises (after L5 laminectomy)

Timm30

Physiotherapy/general

unspecified exercise

Mannion et al25

Aerobics Mannion et al25

Trunk strengthening +

motivational strategies

Friedrich et al20

Home exercise with video

instruction (after lumbar fusion)

Christensen et al17

Home exercise with video instruction

plus group discussion and

support (after lumbar fusion)

Christensen et al17

Lumbar spinal fusion for

spondylolisthesis and/or

severe degeneration

Moller and Hedlund26

Intensive trunk strengthening compared with:

Comparison Author

McKenzie exercise Petersen et al27

Less intensive Manniche et al23

Coordination and proprioception training Johannsen et al 1995

Physical therapy/isometric exercise Manniche et al23

Intensive trunk strengthening plus active

hyper-extension (after disk surgery)

Manniche et al24



18. Danielsen JM, Johnsen R, Kibsgaard SK, Helevik E. Earlyaggressive exercise for post-operative rehabilitation afterdiscectomy. Spine 2000;25:1015-20.

19. Dolan PK, Greenfield K, Nelson RJ, Nelson IW. Can exercisetherapy improve the outcome of microdiscectomy? Spine2000;25:1523-32.

20. Friedrich M, Gittler G, Halberstadt Y, Cermak T, Heiller I.Combined exercise and motivation program: effect on thecompliance and level of disability of patients with chronic lowback pain: a randomized controlled trial. Arch Phys MedRehabil 1998;79:475-87.

21. Johannsen F, Remvig L, Kkryger P, Beck P, Warming S,Lybeck K, et al. Exercises for chronic low back pain: a clinicaltrial. J Orthop Sports Phys Ther 1995;22:52-9.

22. Kankaanpaa MS, Taimela S, Airaksinen O, Hanninen O. Theefficacy of active rehabilitation in chronic low back pain.Effect on pain intensity, self-experienced disability, and lumbarfatigability. Spine 1999;24:1034-42.

23. Manniche C, Lundberg E, Christensen I, Bentzen L, HesselsoeG. Intensive dynamic back exercises for chronic low back pain:a clinical trial. Pain 1991;47:53-63.

24. Manniche C, Asmussen K, Lauritsen BK, Vinterberg H, KarboH, Abildstrup S, et al. Intensive dynamic back exercises with orwithout hyperextension in chronic back pain after surgery forlumbar disc protrusion. A clinical trial. Spine 1993;18:560-7.

25. Mannion AF, Muntener M, Taimela S, Dvorak J. Comparisonof three active therapies for chronic low back pain: results of arandomized clinical trial with one-year follow-up. Rheumatol-ogy 2001;40:77-778.

26. Moller H, Hedlund R. Surgery versus conservative manage-ment in adult isthmic spondylolisthesis—a prospectiverandomized study: part 1. Spine 2000;25:1711-5.

27. Petersen TP, Kryger P, Ekdahl C, Olsen S, Jacobsen S. Theeffect of McKenzie therapy as compared with that of intensivestrengthening training for the treatment of patients withsubacute or chronic low back pain. Spine 2002;27:1702-9.

28. Rittweger J, Just K, Kautzsch K, Reeg P, Felsenberg D.Treatment of chronic low back pain with lumbar extension andwhole-body vibration exercise: a randomized controlled trial.Spine 2002;27:1829-34.

29. Risch SV, Norvell N, Pollock K, Risch ED, Langer H, FultonM, et al. Lumbar strengthening in chronic low back painpatients: physiologic and psychological benefits. Spine1993;18:232-8.

30. Timm KE. A randomized-control study of active and passivetreatments for chronic low back pain following L5 laminec-tomy. J Orthop Sports Phys Ther 1994;20:276-86.

31. Yilmaz F, Yilmaz A, Merdol F, Parlar D, Sahin F, Kuran B.Efficacy of dynamic lumbar stabilization exercise in lumbarmicro-diskectomy. J Rehabil Med 2003;35:163-7.

32. Lindgren KA, Sihvonen T, Leino E, Pitkanen M, Manninen H.Exercise therapy effects on functional radiographic findingsand segmental electromyographic activity in lumbar spineinstability. Arch Phys Med Rehabil 1993;74:933-9.

33. Evyenth O, Hamberg J. Autostretching. Alfta Rehabil Forlag1989;88-9.

34. Peel C, Alland MJ. Cardiovascular responses to isokinetictrunk exercise. Phys Ther 1990;70:503-10.

35. Timm KE. Case studies: use of the cybex trunk extensionflexion unit in the rehabilitation of back patients. J OrthopSports Phys Ther 1987;578-81.

36. Saal JA, Saal JS. Non-operative treatment of herniated lumbarintervertebral disc with radiculopathy. Spine 1989;14:431-7.

37. Assendelft WJJ, Morton SC, Yu EI, Suttorp MJ, Shekelle PG.Spinal manipulative therapy for the low back: a meta-analysis

of effectiveness relative to other therapies. Ann Intern Med2003;138:871-906.

38. Glass GV, McGraw B, Smith ML. Meta-analysis insocial research; chapter 5. Beverly Hills7 Sage Publications;1981. p. 93-152.

39. McKenzie RA. The lumbar spine: mechanical diagnosisand treatment. Waikane (New Zealand)7 Spinal PublicationsLtd; 1981.

40. Farrar JT, Young JP, LaMoreau L, Werth JL, Poole RM. Clinicalimportant changes in chronic pain intensity measured on an11-point numerical pain rating scale. Pain 2001;94:149-58.

41. Davidson M, Keating JL. A comparison of five low backdisability questionnaires: reliability and responsiveness. PhysTher 2002;82:8-24.

42. Fritz JM, Irgang JJ. A comparison of a modified Oswestry lowback pain disability questionnaire and the quebec back paindisability scale. Phys Ther 2001;81:776-88.

Table 2. Summary of exercise programs

Author Description

External

resistance

to ex Stretches

Supervised

program

Home

program

Home

program

compliance

assessed

Christensen et al17

Intervention

PT-supervised sessions: 15 min warm-up ex and

walking with leg/arm swinging; cycling; hopping;

rhythmic back, leg and abdominal ex with

individualized progression by increasing no. of

reps and sets of reps

x U U U U

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Comparison 1 Watch ex video and receive one-time oral

instruction from PT in back, abdominal and

leg ex. Continue at home using written

instructions and video

x U x U x

Comparison 2 Same as for comparison 1, plus 3 � 90 min

meetings with PT and other participants for

group discussion/support over tea/coffee

x U x U x

Danielsen et al18

Intervention

Commenced intervention 4 wk after microdiscectomy;

pulleys and weights for individually tailored ex to

strengthen back, abdominal, and leg muscles

U U U x x

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Comparison Postoperative information about suitable activity

and mild ex; rest and relax, resume-graded activity

and avoid heavy work; individual PT every 2 wk

x U x x x

Dolan et al19

Intervention

PT supervised sessions commenced 6 wk after

microdiscectomy; general aerobic ex: treadmill,

walking, step-ups, dumb-bell lifts; back and hip

stretches; strengthening ex: abdominal curls,

straight leg raise, pelvis and back lifts; each ex

repeated during 2-min sequences and ex speed

increased, as tolerated, throughout intervention

U U U U U

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Comparison No ex or treatment after microdiscectomy x x x x x

Friedrich et al20

Intervention

Submaximal exercise for spinal mobility; trunk,

leg, abdominal strengthening ex; coordination and

endurance ex; gradual progression32,33

x U U U x

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Comparison Same as intervention ex plus 5 counseling

and information sessions; encouragement by

PT; treatment contracts; daily ex diary

x U U U U

Johannsen et al21

Intervention

10-min warm-up on bicycle, double-leg lifts,

trunk lifts, abdominal curls, latissimus pull-down

(with weights) in sitting, hip and knee ex (based on

Manniche et al23

U U U U U

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Comparison 10-min warm-up jogging, coordination ex: standing

and opposite knee to hand, on hands and knees

opposite arm/leg lifts, diagonal sit-ups, balance board

x U U U U

Kankaanpaa et al22

Intervention

Ex for all back movements using resistance equipment;

4 wk very low loads; load increased to subjectively

strenuous in wk 6-8, increased further on wk 9-12

U U U U U

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Comparison Heat and massage to lower back, passive

bnon-exercise–basedQ individual treatment by

PT only during wk 8-12 of intervention period

x x U x x

Manniche et al23

Intervention

Hot pack 15 min; trunk lifts, leg lifts,

abdominal curls, latissimus pull down

(with weights) in sitting; increase 10 reps

each session up to 100 reps by wk 2

U U U ? ?

(continued on next page)



Author

Exercise

without

LBP

Reps per

ex at start

Reps per

ex at end

Session

duration

(min)

No. of

sessions

Program

duration

(wk) Progression

Exercise

progression

decision

rule reported

Christensen et al17

Intervention

U 7-10 ? 90 16 8 U U

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Comparison 1 U ? ? ? ? 8 ? ?

Comparison 2 U ? ? ? ? 8 ? ?

Danielsen et al18

Intervention

U 30 90 40 24 8 U U

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Comparison U ? ? ? 4 8 ? ?

Dolan et al19

Intervention

U ? ? 60 8 4 U U

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Comparison U x x x x 4 x x

Friedrich et al20

Intervention

U ? ? 25 10 4 ? ?

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Comparison U ? ? 25 15 4 U ?

Johannsen et al21

Intervention

x 50 100 60 24 12 U ?

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -Comparison U ? 40 60 24 12 U ?

Kankaanpaa et al22

Intervention

U ? ? 90 24 12 U U

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Comparison U x x ? 4 4 x x

Manniche et al23

Intervention

x 50 100 90 30 12 U U

(continued on next page)

Table 2 (continued )



Author Description

External

resistance

to ex Stretches

Supervised

program

Home

program

Home

program

compliance

assessed

Comparison 1 Same as for Intervention ex but fewer reps U U U ? UComparison 2 Hot pack and massage to lower back, mild

ex: isometric back extension and abdominal

ex and abdominal curls for wk 1-4 with reps

unchanged then no treatment

x x U ? ?

Manniche et al24

Intervention

Hot pack 20 min; trunk and leg lifts

performed to lumbar spine extension,

abdominal curls, latissimus

pull-down ex (with weights) in sitting

U x U x x

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Comparison Same as intervention plus movement into

lumbar spinal hyper-extension

U x U x U

Mannion et al25

Intervention

5-10 min warm-up of cycling and stepping;

trunk strengthening ex using resistance

equipment at submaximal effort

U U U x x

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Comparison 1 10 min warm-up, 20 min low-impact aerobics,

20-30 min trunk and leg ex

x U U x x

Comparison 2 Individual PT to increase functional capacity

with strengthening, coordination and aerobic

ex, ergonomic education and home ex

x ? U U ?

Moller et al26

Intervention

12 back and abdominal ex (4 ex using pulleys and

leg press and 8 ex with no equipment); in addition,

the 8 bno equipmentQ ex performed at home

x ? U U x

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Comparison Lumbar fusion surgery F brace; no ex x x x x x

Petersen et al27

Intervention

5-10 min cycle, 10 min general warm-up

and spine movements; trunk lifting,

leg lifting, abdominal curls, latissimus

pull down (with weights) in sitting

(based on Manniche et al23

U U U U U

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Comparison McKenzie unloaded spinal self-mobilizing ex x x U U ?

Timm et al30

Intervention

Cycle 10 min to tolerance, trunk strengthening on

dynamometers at 10 reps each at low and

high speeds34,35

U x U x U

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Comparison 1 McKenzie-type and trunk strengthening

ex: bridging, abdominals, alternate arm

and leg raises, squats, lunges; home

ex: 20 reps each ex

x U U U U

Comparison 2 No ex or treatment after L5 laminectomy x x x x x

Yilmaz et al31

Intervention

Commence 5 wk after surgery;

warm-up, abdominal ex, bridging + hip/leg

extension, on hands and knees arm/leg lifts,

forward/sideways lunging, squats36

x U U ? U

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Comparison 1 Spinal flexion and McKenzie extension

ex, pelvic tilt, abdominal and trunk

strengthening ex. Demonstrated then

written to continue at home; at wk 2,

10 reps and at wk 3, 15 reps each ex

x U x U U

Comparison 2 No ex or treatment after microdiscectomy x x x x x

PT, physical therapist/physical therapy; ex, exercises; reps, repetitions; U , yes; x, no; ?, unable to determine from report.




Author

Exercise

without

LBP

Reps per

ex at start

Reps per

ex at end

Session

duration

(min)

No. of

sessions

Program

duration

(wk) Progression

Exercise

progression

decision

rule reported

Comparison 1 x 20 20 45 30 12 x UComparison 2 U 10 10 60 8 4 x U

Manniche et al24

Intervention

x 50 50 60-90 24 12 x U

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Comparison x 50 50 60 to 90 24 12 x U

Mannion et al25

Intervention

U 25 ? 60 24 12 U ?

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Comparison 1 U ? ? 60 24 12 ? ?

Comparison 2 U ? ? 30 24 12 U ?

Moller et al26

Intervention

U ? ? 45 130 52 ? ?

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Comparison U x x x x 26 x x

Petersen et al27

Intervention

x 50 100 60-90 15 8 U x

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Comparison U ? ? 30 15 8 ? ?

Timm et al30

Intervention

U 10 ? ? 24 8 U ?

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Comparison 1 U 30 ? ? 24 8 ? ?

Comparison 2 U x x x x x x x

Yilmaz et al31

Intervention

U 15 45 ? 24 8 U x

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Comparison 1 U 5 15 ? 24 8 U U

Comparison 2 U x x x x x x x




Table 3. Effects of trunk-strengthening exercise on pain and functional ability

Short-term (12 wk) Sample

size

(total)

Method

score

(0-10) Comparison

SMD (95% CI)

Long-term (52 wk) Pain Function

Section 1: Strengthening exercises for chronic low back pain

Trunk-strengthening exercise vs no exercise:

Kankaanpaa et al22 (s/t) 54 6 0.33 (�0.21 to 0.87) 0.01 (�0.53 to 0.55)

Kankaanpaa et al22 (l/t) 49 0.95 (0.35 to 1.55) 0.50 (�0.07 to 1.07)

Trunk-strengthening exercise vs trunk strengthening with motivation:

Friedrich et al20 (s/t) 84 7 �0.32 (�0.78 to 0.14) �0.26 (�0.72 to 0.20)

Friedrich20 1998 (l/t) 69 �0.70 (�1.18 to �0.22) �0.43 (�0.91 to 0.05)

Trunk strengthening exercise vs other types of exercise programs:

Mannion et al25 (s/t) 64 7 PT 0.04 (�0.49 to 0.57) �0.02 (�0.55 to 0.51)

Mannion et al25 (s/t) 63 7 aerobics 0.00 (�0.53 to 0.53) �0.10 (�0.63 to 0.43)

Manniche et al24 (s/t) 53 6 PT N/A 0.14 (�0.40 to 0.68)

Pooled effect: 0.02 (�0.35 to 0.40) 0.00 (�0.31 to 0.31)

Mannion et al25 (l/t) 64 7 PT 0.11 (�0.42 to 0.64) 0.33 (�0.21 to 0.86)

Mannion et al25 (l/t) 63 7 aerobics 0.07 (�0.46 to 0.60) 0.09 (�0.44 to 0.62)

Manniche et al24 (l/t) 53 6 PT N/A 0.21 (�0.41 to 0.83)

Pooled effect: 0.10 (�0.27 to 0.48) 0.22 (�0.10 to 0.54)

Intensive trunk-strengthening exercise vs other types of exercise programs:

Johannsen et al21 (s/t) 27 6 coordination 1.09 (0.54-1.68) 0.45 (�0.09 to 0.99)

Manniche et al (s/t) 37 6 PT/exercise N/A 0.76 (0.19-1.33)

Manniche et al23 (s/t) 42 6 less intensive trunk N/A 0.62 (0.05-1.16)

Pooled effect: N/A 0.58 (0.22-0.94)

Johannsen et al21 (l/t) 27 6 coordination 0.00 (�0.53 to 0.53) 0.45 (�0.09 to 0.99)

Manniche et al23 (l/t) 29 6 PT/exercise N/A 1.14 (0.47-1.82)

Manniche et al23 (l/t) 40 6 less intensive trunk N/A 0.84 (0.28-1.40)

Pooled effect: N/A 0.77 (0.33-1.20)

Intensive trunk-strengthening exercise vs McKenzie:

Petersen et al27 (s/t) 260 7 McKenzie �0.29 (�0.54 to �0.05) �0.04 (�0.28 to 0.21)

Petersen et al27 (l/t) 260 7 McKenzie �0.31 (�0.55 to �0.06) �0.15 (�0.39 to 0.09)

Section 2: Strengthening exercises for CLBP after lumbar surgery

Trunk-strengthening exercise vs lumbar fusion (spondylolisthesis/degeneration):

Moller and Hedlund 26 (l/t) 98 6 �0.50 (�0. 99, �0.01) �0.76 (�1.25, �0.26)

Trunk strengthening vs other types of exercise programs (after fusion):

Christensen et al17 (s/t) 39 6 Video/home exercise 0.27 (�0.39 to 0.92) N/A

Christensen et al17 (s/t) 42 6 Behavioral therapy 0.00 (�0.67 to 0.67) N/A

Pooled effect: 0.14 (�0.33 to 0.61) N/A

Christensen et al17 (l/t) 39 6 Video/home exercise 0.07 (�0.58 to 0.73) N/A

Christensen et al17 (l/t) 42 6 Behavioral therapy �0.17 (�0.83 to 0.50) N/A

Pooled effect: �0.04 (�0.50 to 0.43) N/A

Trunk-strengthening exercise vs no exercise:

Danielsen et al18 (s/t) 63 9 0.22 (�0.29 to 0.73) 0.50 (�0.02 to 1.01)

Dolan et al19 (s/t) 20 7 0.35 (�0.54 to 1.23) 0.47 (�0.42 to 1.37)

Yilmaz et al31 (s/t) 21 6 1.66 (0.59 to 2.72) 1.48 (0.59 to 2.72)

Timm30 (s/t) 75 6 N/A 1.19 (0.76-1.61)

Pooled effect: 0.70 (�0.19 to 1.59) 1.08 (0.76-1.41)

Danielsen31 2000 (l/t) 63 9 0.17 (�0.34 to 0.68) 0.37 (�0.15 to 0.88)

Dolan et al19 (l/t) 20 7 0.47 (�0.42 to 1.37) 0.79 (�0.13 to 1.72)

Pooled effect: 0.26 (�0.18 to 0.71) 0.53 (0.03-1.04)

Trunk-strengthening exercise vs other types of exercise programs:

Yilmaz et al31 (s/t) 21 6 Trunk ex and McKenzie 0.89 (�0.07 to 1.84) 1.05 (0.09-2.00)

Timm30 (s/t) 75 6 Trunk ex and McKenzie N/A �0.03 (�0.51 to 0.45)

Pooled effect: N/A 0.37 (�0.58 to 1.33)

Intensive trunk strengthening vs intensive trunk strengthening + hyperextension:

Manniche24 (s/t) 47 8 N/A 0.81 (0.21-1.42)

s/t, Short-term; l/t, long-term.



Documents

Trunk-Strengthening Exercises for Chronic Low Back Pain: A Systematic Review