Ann Rehabil Med.  2017 Oct;41(5):793-800. 10.5535/arm.2017.41.5.793.

Reliability and Validity of a New Method for Isometric Back Extensor Strength Evaluation Using A Hand-Held Dynamometer

Affiliations
  • 1Department of Rehabilitation Medicine, Kangwon National University Hospital, Kangwon National University School of Medicine, Chuncheon, Korea. sora.baek@kangwon.ac.kr
  • 2Center for Farmers' Safety and Health, Kangwon National University Hospital, Chuncheon, Korea.
  • 3Gangwon-Do Rehabilitation Hospital, Chuncheon, Korea.

Abstract


OBJECTIVE
To investigate the reliability and validity of a new method for isometric back extensor strength measurement using a portable dynamometer.
METHODS
A chair equipped with a small portable dynamometer was designed (Power Track II Commander Muscle Tester). A total of 15 men (mean age, 34.8±7.5 years) and 15 women (mean age, 33.1±5.5 years) with no current back problems or previous history of back surgery were recruited. Subjects were asked to push the back of the chair while seated, and their isometric back extensor strength was measured by the portable dynamometer. Test-retest reliability was assessed with intraclass correlation coefficient (ICC). For the validity assessment, isometric back extensor strength of all subjects was measured by a widely used physical performance evaluation instrument, BTE PrimusRS system. The limit of agreement (LoA) from the Bland-Altman plot was evaluated between two methods.
RESULTS
The test-retest reliability was excellent (ICC=0.82; 95% confidence interval, 0.65-0.91). The Bland-Altman plots demonstrated acceptable agreement between the two methods: the lower 95% LoA was −63.1 N and the upper 95% LoA was 61.1 N.
CONCLUSION
This study shows that isometric back extensor strength measurement using a portable dynamometer has good reliability and validity.

Keyword

Back muscles; Isometric contraction; Muscle strength dynamometer; Reproducibility of results

MeSH Terms

Back Muscles
Female
Humans
Isometric Contraction
Loa
Male
Methods*
Muscle Strength Dynamometer
Reproducibility of Results*

Figure

  • Fig. 1 Device setting for isometric back extensor strength evaluation with portable dynamometer. (A) Portable dynamometer (Power Track II Commander Muscle Tester; JTECH Medical, Midvale, UT, USA) composed of a compression force sensor (left) and a control/recording unit (right). (B) Square back plate. This wooden plate interface with subjects' back muscle and transmit compression pressure to the attached force sensor unit. (C) Specially designed chair. Vertical linear groove in seatback center is designed for holding a sensor unit with a ruler to set the sensor unit in a specific height. (D) Subject seated in the chair and the pelvis fixed by fastening the seat belt. Square back plate was shown in the red elliptical circle between chair seatback and subjects. The force sensor unit is not visible because it is inserted into the center groove of the chair.

  • Fig. 2 Isometric back extensor strength evaluation with isokinetic dynamometer machine (PrimusRS; BTE Technologies Inc., Hanover, MD, USA).

  • Fig. 3 Correlation between PrimusRS and new method (p<0.001).

  • Fig. 4 Bland-Altman plot for muscle strength data. Dotted line indicates 95% limits of agreement ranging from −63.1 to 61.1 N.


Cited by  1 articles

Comprehensive Physical Work Capacity Evaluations for Korean Farmers Assessed in Healthy Volunteers
Seungsu Jeong, Gowun Kim, Hee-won Park, Sora Baek
Ann Rehabil Med. 2023;47(6):468-482.    doi: 10.5535/arm.23055.


Reference

1. Little P, Smith L, Cantrell T, Chapman J, Langridge J, Pickering R. General practitioners' management of acute back pain: a survey of reported practice compared with clinical guidelines. BMJ. 1996; 312:485–488. PMID: 8597683.
Article
2. Chok B, Lee R, Latimer J, Tan SB. Endurance training of the trunk extensor muscles in people with subacute low back pain. Phys Ther. 1999; 79:1032–1042. PMID: 10534796.
Article
3. Kaser L, Mannion AF, Rhyner A, Weber E, Dvorak J, Muntener M. Active therapy for chronic low back pain: part 2. Effects on paraspinal muscle cross-sectional area, fiber type size, and distribution. Spine (Phila Pa 1976). 2001; 26:909–919. PMID: 11317113.
4. Moon HJ, Choi KH, Kim DH, Kim HJ, Cho YK, Lee KH, et al. Effect of lumbar stabilization and dynamic lumbar strengthening exercises in patients with chronic low back pain. Ann Rehabil Med. 2013; 37:110–117. PMID: 23525973.
Article
5. Singh DK, Bailey M, Lee R. Decline in lumbar extensor muscle strength the older adults: correlation with age, gender and spine morphology. BMC Musculoskelet Disord. 2013; 14:215. PMID: 23875830.
Article
6. Cho KH, Beom JW, Lee TS, Lim JH, Lee TH, Yuk JH. Trunk muscles strength as a risk factor for nonspecific low back pain: a pilot study. Ann Rehabil Med. 2014; 38:234–240. PMID: 24855618.
Article
7. Bayramoglu M, Akman MN, Kilinc S, Cetin N, Yavuz N, Ozker R. Isokinetic measurement of trunk muscle strength in women with chronic low-back pain. Am J Phys Med Rehabil. 2001; 80:650–655. PMID: 11523967.
8. Keller A, Hellesnes J, Brox JI. Reliability of the isokinetic trunk extensor test, Biering-Sørensen test, and Astrand bicycle test: assessment of intraclass correlation coefficient and critical difference in patients with chronic low back pain and healthy individuals. Spine (Phila Pa 1976). 2001; 26:771–777. PMID: 11295899.
9. Hanada EY, Hubley-Kozey CL, McKeon MD, Gordon SA. The feasibility of measuring the activation of the trunk muscles in healthy older adults during trunk stability exercises. BMC Geriatr. 2008; 8:33. PMID: 19055822.
Article
10. Lee HJ, Lim WH, Park JW, Kwon BS, Ryu KH, Lee JH, et al. The relationship between cross sectional area and strength of back muscles in patients with chronic low back pain. Ann Rehabil Med. 2012; 36:173–181. PMID: 22639740.
Article
11. Bernard JC, Boudokhane S, Pujol A, Chaleat-Valayer E, Le Blay G, Deceuninck J. Isokinetic trunk muscle performance in pre-teens and teens with and without back pain. Ann Phys Rehabil Med. 2014; 57:38–54. PMID: 24360320.
Article
12. Hutten MM, Hermens HJ. Reliability of lumbar dynamometry measurements in patients with chronic low back pain with test-retest measurements on different days. Eur Spine J. 1997; 6:54–62. PMID: 9093828.
Article
13. Yahia A, Ghroubi S, Kharrat O, Jribi S, Elleuch M, Elleuch MH. A study of isokinetic trunk and knee muscle strength in patients with chronic sciatica. Ann Phys Rehabil Med. 2010; 53:239–244. 244–249. PMID: 20381442.
Article
14. Weir JP. Quantifying test-retest reliability using the intraclass correlation coefficient and the SEM. J Strength Cond Res. 2005; 19:231–240. PMID: 15705040.
Article
15. Bland JM, Altman DG. Statistical methods for assessing agreement between two methods of clinical measurement. Lancet. 1986; 1:307–310. PMID: 2868172.
Article
16. Rantanen J, Rissanen A, Kalimo H. Lumbar muscle fiber size and type distribution in normal subjects. Eur Spine J. 1994; 3:331–335. PMID: 7532536.
Article
17. Gruther W, Wick F, Paul B, Leitner C, Posch M, Matzner M, et al. Diagnostic accuracy and reliability of muscle strength and endurance measurements in patients with chronic low back pain. J Rehabil Med. 2009; 41:613–619. PMID: 19565154.
Article
18. Pengel HM, Maher CG, Refshauge KM. Systematic review of conservative interventions for subacute low back pain. Clin Rehabil. 2002; 16:811–820. PMID: 12501942.
Article
19. Mayer J, Mooney V, Dagenais S. Evidence-informed management of chronic low back pain with lumbar extensor strengthening exercises. Spine J. 2008; 8:96–113. PMID: 18164458.
Article
20. Scharrer M, Ebenbichler G, Pieber K, Crevenna R, Gruther W, Zorn C, et al. A systematic review on the effectiveness of medical training therapy for subacute and chronic low back pain. Eur J Phys Rehabil Med. 2012; 48:361–370. PMID: 22820818.
21. Graves JE, Webb DC, Pollock ML, Matkozich J, Leggett SH, Carpenter DM, et al. Pelvic stabilization during resistance training: its effect on the development of lumbar extension strength. Arch Phys Med Rehabil. 1994; 75:210–215. PMID: 8311680.
Article
22. da Silva RA, Lariviere C, Arsenault AB, Nadeau S, Plamondon A. Pelvic stabilization and semisitting position increase the specificity of back exercises. Med Sci Sports Exerc. 2009; 41:435–443. PMID: 19127180.
Article
23. da Silva RA, Lariviere C, Arsenault AB, Nadeau S, Plamondon A. Effect of pelvic stabilization and hip position on trunk extensor activity during back extension exercises on a Roman chair. J Rehabil Med. 2009; 41:136–142. PMID: 19229445.
Article
24. Maud PJ, Foster C. Physiological assessment of human fitness. 2nd ed. Champaign, IL: Human Kinetics;2006. p. 131–138.
25. Limburg PJ, Sinaki M, Rogers JW, Caskey PE, Pierskalla BK. A useful technique for measurement of back strength in osteoporotic and elderly patients. Mayo Clin Proc. 1991; 66:39–44. PMID: 1824867.
Article
26. Sinaki M, Khosla S, Limburg PJ, Rogers JW, Murtaugh PA. Muscle strength in osteoporotic versus normal women. Osteoporos Int. 1993; 3:8–12.
Article
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