Int J Physiother Res 2015;3(4):1156-62. ISSN 2321-1822 1156

Original Article

LOAD EQUIVALENCE OF TRANSIENT DEFORMATION CHARACTER-ISTICS OF EXERCISE ELASTIC TUBES USED IN PHYSIOTHERAPYREHABILITATION AND FITNESS TRAINING PROGRAMSR.Vinodh Rajkumar.Founder: PALEOLITHICX, Physiotherapist & Functional Fitness Training Instructor (Private practi-tioner), Bangalore, Karnataka, India.

Introduction: Exercise elastic tubes (EET) have been used in Fitness training and Physiotherapy rehabilitationprograms. Although we have practically felt the behavior of different levels of elastic resistance devices but theexact amount of opposing force they produce are not well understood, hence this lack of knowledge can reducethe quality of exercise prescriptions. Based on the findings of simple experiments done with EET, this articleunfolds the scope for inexpensively studying the load equivalence (in kilograms) of different levels of EET forrefined physiotherapy rehabilitation and fitness training practices.Materials and Methods: The objective of this experiment was to understand the lengthening and thicknessdeformation behavior of EET using different loads so that the load equivalency of a particular elongation orlengthening effect can be used in refining the exercise prescription standards. The changes in length of EET weremeasured using inch tape whilst the changes in thickness of EET were measured using the vernier caliper.Results: The data of transient deformation of LEVEL-3 and LEVEL-5 EET in different feasible loading conditionsshows strong negative correlation between the thickness and length of EET. The doubling of the original lengthwas obtained with 7.5 Kg load for LEVEL-3 EET and 15 Kg load for LEVEL-5 EET which reflects their resistance level(modulus of elasticity) designed for appropriate strength training programs. Another innovative experimentwas also conducted in which two LEVEL-3 EET were subjected together as a composite unit and their response todifferent loads was also observed and hypothesized as possible behavior of Level-6 EET.Discussion: The results obviously gives the load equivalence features in kilograms for particular level ofelongation of EET instead of merely selecting and applying different levels of EET without knowing how muchresistive force they can afford for strength training purposes.Conclusion: Though an inexpensive method of discovering the load equivalence of EET was discussed throughoutthis article, a furthermore safe and sophisticated laboratory to test all available levels of EET is stronglyrecommended because, if the loaded elastic material ruptures it can sabotage anything around it.KEY WORDS: Elastic Tubes, Resistance Bands, Load Equivalence, Thickness And Elongation Of Elastic Tubes,Elastic Resistance Exercise.

ABSTRACT

INTRODUCTION

Address for correspondence: R.Vinodh Rajkumar, # 638, 1st Floor, Jakkuramma Building, BehindEswara Temple, 1st Cross, 1st Main, Mathikere, Bangalore-560054, Karnataka, India.Mobile: +919008424632 E-Mail: dreamofkalam@rediffmail.com

International Journal of Physiotherapy and Research,Int J Physiother Res 2015, Vol 3(4):1156-62. ISSN 2321-1822

DOI: http://dx.doi.org/10.16965/ijpr.2015.160

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International Journal of Physiotherapy and ResearchISSN 2321- 1822

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DOI: 10.16965/ijpr.2015.160

Received: 18-06-2015Peer Review: 18-06-2015Revised: None

Accepted : 13-07-2015Published (O): 11-08-2015Published (P): 11-08-2015

Exercise elastic tubes (EET) have been commonlyused in Fitness training and Physiotherapyrehabilitation programs. Elastic tubing could be

an inexpensive alternative for people who wantto perform strength training but do not haveaccess to more expensive or sophisticatedequipment [1]. Joseph B Myers et al recommen-

Int J Physiother Res 2015;3(4):1156-62. ISSN 2321-1822 1157

R.Vinodh Rajkumar. LOAD EQUIVALENCE OF TRANSIENT DEFORMATION CHARACTERISTICS OF EXERCISE ELASTIC TUBES USED IN PHYSIO-THERAPY REHABILITATION AND FITNESS TRAINING PROGRAMS.

METERIALS AND METHODS

-ded seven resistance exercises with rubber tubeas pre-throwing warm up routines for throwers[2]. Elastic bands are frequently used forresistance training; however the selection of thebands to progress through the levels of elasticresistance is done in a subjective manner dueto the lack of quantitative data on the value ofthe material’s resistance as a function of itstension [3]. Mechanical tests done by MartinsWR et al revealed different elastic forces fordifferent levels of elongation of each tube andrecommended for the replication of the resultsin clinical situations, so the elastic resistancein clinical routine could be evaluated with morepropriety [4]. The prediction of maximum tensionvalues of elastic tubing for any given elongationis possible by simple variation of resting length[5]. Although we have practically felt thebehavior of different levels of elastic resistancedevices but the exact amount of opposing forcethey produce are not well understood, hence thislack of knowledge can reduce the quality ofexercise prescriptions. Based on the findings ofsimple experiments done with EET, this articleunfolds the scope for inexpensively studying theload equivalence (in kilograms) of differentlevels of EET for refined physiotherapy rehabili-tation and fitness training practices.

The objective of this experiment was tounderstand the lengthening and thicknessdeformation behavior of EET using differentloads in a readily available non-laboratory setup, so that the load equivalency (in kilograms)of a particular elongation or lengthening effectcan be used in refining the exercise prescriptionstandards. The term non-laboratory set upindicates the gym environment which was notintended to do such experiments but the analysishad to be carried out with minimum availableresources and continual creativity, at par withsafety precautions because, if the loaded elasticmaterial ruptures it can sabotage anythingaround it. The minimum resources opted toconduct this experiment was (a) Level-3 exerciseelastic tube (b) Level -5 exercise elastic tube(c) Inch tape (d) Vernier caliper (e) Technogymbarbell plates - 2.5 Kg, 5 Kg, 10 Kg and someadditional loads if required in this same range

and (f) Supporting bar to secure the EET, so smithmachine was found suitable.The EET was made double its length by forminga loop around the supporting bar and therequired load was applied on the handles of theEET which is named as Looped loadingexperiment. As expected, increase in the lengthand decrease in the thickness (or diameter) ofEET was noticeable under loading conditions.The changes in length were measured using inchtape in the vertical portion of the EET(Photograph-1) and the changes in thicknesswere measured using the vernier caliper(Photograph-2). A semicircular area of EEThooking on to the supporting bar (SB) wasconsistently found to be 7 cm long (Figure-1)but for simplicity, only the changing dimensionsin the vertical portion of EET was observed andmeasured. Figure-2 schematically showslengthening and thinning effect on the EET indifferent loading conditions with the SB locatedat 195 cm above the ground level, so theexperiment had to be conducted within thisvertical limit. After making a loop around theSB, the handles of the EET were passed throughthe central opening of the barbell plates(Photograph-3) which normally gives a facilityto effectively secure the load to stress andelongate this elastic tube. The length andthickness of the Level - 3 and Level-5 EET atrest and loaded conditions (2.5 Kg, 5 Kg, 7.5 Kg,10 Kg and 12.5 Kg) were measured andcompared. In fact, because of the higher materialstiffness, Level-5 EET could be additionallytested with 15 Kg, 17.5 Kg and 20 Kg. The originaldimension of Level-3 and Level-5 EET at rest

Photograph 1: Thevertical portion oflooped EET was measur-ed using inch tape forunder-standing themagnitudeof elonga-tion under differentloading conditions ascompared to its lengthat rest.

Int J Physiother Res 2015;3(4):1156-62. ISSN 2321-1822 1158

R.Vinodh Rajkumar. LOAD EQUIVALENCE OF TRANSIENT DEFORMATION CHARACTERISTICS OF EXERCISE ELASTIC TUBES USED IN PHYSIO-THERAPY REHABILITATION AND FITNESS TRAINING PROGRAMS.

after getting looped around the supporting barwas 55 cm long with 10.1 mm thickness and 62cm with 10.3 mm thickness, respectively, andboth these elastic tubes were able to regain theiroriginal dimension between all loadingexperiments (Photograph-4, 5 & 6).Photograph 2: The thickness (diameter) of looped EETwas measured using vernier caliper under differentloading conditions as compared to its original thicknessat rest.

Fig. 1: Schematic side view of the experimental set upwith the EET under loading with a barbell plate. A semi-circular area of EET of about 7 cm was constantly foundwrapping the upper and side portions of SB but this por-tion was found completely flattened and thinned underloading conditions. The diameter of the supporting barwas 2.8 cm.

Fig 2: Schematically shows theobservable characteristics ofEET in different loading condi-tions. The supporting bar waslocated at 195 cm from theground level and this had set avertical limit to conduct thestudy with further higher loads.It should be noted here, that thisis just a schematic representa-tion of the EET’s behavior not theexperimental set up with seriallyarranged EET.

Photograph 3: Shows the facility to secure the barbellplate by passing the handles of the EET through itscentral opening.

Photograph 4: Shows the LEVEL-3 EET (Brand name -CHAMP) and the LEVEL-5 EET (Brand name - Reebok). Thethickness or diameter of LEVEL -3 EET at rest was 10.1mm and of LEVEL-5 EET at rest was 10.3 mm.

Level 3 FET Level 4 FET

Photograph 5: Shows the total length of the elasticportions of LEVEL-3 EET (115 cm) at rest and the LEVEL-5EET (132 cm) at rest. After getting looped around the SB,at rest LEVEL -3 EET was 55 cm long with 10.1 mmthickness and LEVEL-5 EET 62 cm with 10.3 mm thickness.

Int J Physiother Res 2015;3(4):1156-62. ISSN 2321-1822 1159

R.Vinodh Rajkumar. LOAD EQUIVALENCE OF TRANSIENT DEFORMATION CHARACTERISTICS OF EXERCISE ELASTIC TUBES USED IN PHYSIO-THERAPY REHABILITATION AND FITNESS TRAINING PROGRAMS.

Photograph 6: Shows the thickness of the elasticportions of LEVEL-3 EET (2.5 mm excluding the tubularportion) at rest and the LEVEL-5 EET (4.5 mm excludingthe tubular portion) at rest. But this thickness could notbe measured during loading conditions though it musthave undergone principal changes to decrease the di-ameter and increase the length of the EET.

RESULTS AND TABLESThe data of transient deformation of LEVEL-3and LEVEL-5 EET in different feasible loadingconditions can be found in table-1 & 2. Theinverse relationship between the thickness andlength of EET under loading conditions is alsomade evident. In the looped loading experiment,the doubling of the original length of EET wasobtained with 7.5 Kg load for LEVEL-3 EET and15 Kg load for LEVEL-5 EET which reflects theirresistance level (modulus of elasticity) designedfor appropriate strength training programs.Another innovative experiment was alsoconducted in which two LEVEL-3 EET weresubjected together as a composite unit (bypassing all 4 handles through the central openingof a single barbell plate) and their possiblebehavior as Level-6 EET to different loads canbe found in table-3. Comparison graphs 1, 2 & 3displays the transient deformation characteri-stics of EET in all these three major experiments.Table 1: (LOOPED LOADING EXPERIMENT: 1) Elongationand thickness characteristics of LEVEL-3 EET under dif-ferent loading conditions. There is a strong negativecorrelation between thickness and maximum elongation(r = - 0.9912)

At rest - 10.1 55 -

Under tension 2.5 10 64.5 9.5

Under tension 5 9 81 26

Under tension 7.5 8 104 49

Under tension 10 7 140 85

Under tension 12.5 6 175 120

Status of the EET

Maximum elongation

(cm)

Length gain (cm)

Thickness (mm)

Load (Kg)

Table 2: (LOOPED LOADING EXPERIMENT: 2) Elongationand thickness characteristics of LEVEL-5 EET under dif-ferent loading conditions. There is a strong negativecorrelation between thickness and maximum elongation(r = - 0.9772).

At rest - 10.3 62 -

Under tension 2.5 10.2 70 8

Under tension 5 10.2 77 15

Under tension 7.5 10.1 83 21

Under tension 10 10 94 32

Under tension 12.5 9 107 45

Under tension 15 8.5 125 63

Under tension 17.5 7.5 140 78

Under tension 20 7 164 102

Status of the EET

Maximum elongation

(cm)

Load (Kg)

Thickness (mm)

Length gain (cm)

Table 3: (LOOPED LOADING EXPERIMENT: 3) Elongationand thickness characteristics of possible LEVEL-6 EET(two LEVEL-3 EET were subjected together as a compositeunit) under different loading conditions. There is a strongnegative correlation between thickness and maximumelongation (r = - 0.9783). Such composite arrangementof two elastic tubes can be used for obtaining greaterresistances to strength training for suitable individuals,in the absence of higher level EET.

At rest - 10.1 55 -

Under tension 2.5 10.05 58 3

Under tension 5 9.5 63 8

Under tension 7.5 9 69 14

Under tension 10 8.5 75 20

Under tension 12.5 8 84 29

Under tension 15 7.5 99 44

Under tension 17.5 7 114 59

Under tension 20 6.5 127 72

Length gain (cm)

Status of the EET

Maximum elongation

(cm)

Thickness (mm)

Load (Kg)

Graph 1: The maximum elongated length of EET at restand during different loading conditions.

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R.Vinodh Rajkumar. LOAD EQUIVALENCE OF TRANSIENT DEFORMATION CHARACTERISTICS OF EXERCISE ELASTIC TUBES USED IN PHYSIO-THERAPY REHABILITATION AND FITNESS TRAINING PROGRAMS.

Graph 2: The thickness of EET at rest and during differ-ent loading conditions.

Graph 3: The length gains of EET at rest and duringdifferent loading conditions.

DISCUSSIONThese results obviously gives the loadequivalence features in kilograms for particularlevel of elongation of EET instead of merelyselecting and applying different levels of EETwithout knowing how much resistive force theycan afford for strength training purposes.Although not discussed in detail, during thesethree major experiments, other modifiedexperiments were also done (Photograph - 7, 8& Figure-3). The vertical limit (Figure-2) andextension of the experiments with higher loadsby stacking more than one load (Photograph-9)were the factors posing difficulties during thisexperiment; hence further improvisation increating a safe, inexpensive and experiment-friendly atmosphere is warranted.Photograph 7: This is non-looped loading butit poses practical difficulties in doingexperiments with higher loads as the maximumelongation requires enough space andmeasurable atmosphere. The transientdeformation characteristics of EET in thisexperiment was found to be equal to the effectcaused by just one load in the looped loadingexperiments discussed earlier and theexperiment discussed in Photograph-8 . Forexample, the effects of 2.5 Kg load in non-looped

loading was equal to the effect caused by (a)looped loading with 2.5 Kg loads for eachhandles and (b) looped loading with a 5 Kg loadhooked commonly to both handles. Themaximum elongation of EET in non-loopedloading is almost equal to the sum of maximumelongation of EET on both the sides in loopedloading. To be clearer, the maximum elongationof LEVEL-3 EET in non-looped loading with 2.5Kg was 166 cm but in looped-loading themaximum elongation on both sides was 81 cm(81 cm + 81 cm = 162 cm) excluding the lengthof semicircular portion of EET, so equal deforma-tion effects of all the three different techniqueswas observed.

Photograph 7

Fig. 3: Equal effect possibilities with non-looped loading,looped loading and looped-paired loading. The transientdeformation effects caused by load (L) in non-loopedloading can be found equal in looped loading if (i) theload (L) is doubled and applied as a single load (2L) and(ii) as paired loading (L & L).

Photograph 8: Looped and paired loading with two simi-lar loads hooked to the handles separately. (Relate pho-tograph-7 and figure-3).

Int J Physiother Res 2015;3(4):1156-62. ISSN 2321-1822 1161

R.Vinodh Rajkumar. LOAD EQUIVALENCE OF TRANSIENT DEFORMATION CHARACTERISTICS OF EXERCISE ELASTIC TUBES USED IN PHYSIO-THERAPY REHABILITATION AND FITNESS TRAINING PROGRAMS.

Photograph 9: Stacking additional loads andexperimenting furthermore is interesting but requiresmanual effort and gradual incremental loadingtechniques to avoid any injurious consequences causedby rupturing of the EET. Actually this was a single-handedexperiment which demanded patience and appropriateenergy levels while conducting all these experiments.

The purpose of this study is to relate the loadequivalence with dimensions of the EET for prac-tical applications in all the exercise techniquesperformed with EET. For instance, the individualshown in the photograph- 10 performed singlearm chest press with static forward lunge withLEVEL-3 EET looped around a vertical beam. Thelength of this EET at the starting position andfinish position was 82 cm and 146 cm, respecti-

Photograph 10: This technique is called single arm chestpress with static lunge posture using LEVEL-3 EET andwhen this individual was performing this technique (a)the start position brought the length of EET to 82 cm and(b) the finish position brought the length of EET to 146cm. Based on table-1, the 82 cm = 5 Kg and 146 cm = 10Kg, approximately. This EET elongation is also highlyindividual-specific based on the muscular strength andanthropometric characteristics like upper extremitylength.

vely. Based on table-1, the 82 cm elongation isequal to 5 Kg load and 146 cm elongation is equalto 10 Kg load approximately, which means hehad to impart muscular force in the range of 5 -10 Kg. This is how load equivalence can befigured out for changing dimensions of EETduring exercise. If this same task should bedecreased or increased in intensity, then thestanding position of the exerciser can be movedcloser to or farther from the support bar, respec-tively. The force of elastic resistance dependson percentage of elongation, regardless ofinitial length and typical clinical elongationsrarely exceed 200 % [6].The importance of EET in the field of exercise iswell established. “Both elastic resistance andfree-weight resistance (such as barbells anddumbbells) have several similar properties: (a)both provide some form of resistance, (b) bothallow a free range of motion, (c) both allowvariable speed of movement, and (d) both allowprogressive resistance and all four of these prop-erties are critical for the benefits offered byeffective resistance-training programs. Withelastic tubing, on the other hand, you can haveresistance when doing exercises in a horizontalplane” [7]. Valid exercise innovations for shoul-der joint using resistance bands, medicine ball,free weights and strength training machines willhappen by understanding the humeral headspinning styles [8]. Home-based resistancetraining programs utilizing elastic tubing canserve as a practical and effective means ofeliciting strength gains in adults over the age of65 [9]. Further research works on the basis ofthese experimental findings can lead to nextlevel standardization of exercise prescriptionswith EET.

CONCLUSION

Though an inexpensive method of discoveringthe load equivalence of EET was discussedthroughout this article, a furthermore safe andsophisticated laboratory to test all available lev-els of EET is strongly recommended. The wholeexperiment was done on the support bar whosediameter was 2.8 cm so the behavior of the EETused in this study on a different support bar withhigher or lesser diameter than 2.8 cm is yet tobe explored. Possibilities are there that the EET

Int J Physiother Res 2015;3(4):1156-62. ISSN 2321-1822 1162

R.Vinodh Rajkumar. LOAD EQUIVALENCE OF TRANSIENT DEFORMATION CHARACTERISTICS OF EXERCISE ELASTIC TUBES USED IN PHYSIO-THERAPY REHABILITATION AND FITNESS TRAINING PROGRAMS.

Conflicts of interest: None

REFERENCES

of same category may respond slightly differ-ent to same loads. Periodic re-evaluation of theEET on the basis of the looped or non-loopedloading experiments in clinical and fitness train-ing set ups may reveal any permanent alter-ations in its dimensions caused by over usageand impending risk of damage. In fact, this sortof experiments must be pursued in the under-graduate level of Physiotherapy for scientificutilization of exercise elastic tubes in Physio-therapy rehabilitation and Fitness trainingprograms. If load equivalence and transientdeformation characteristics of EET are known,then deriving particular load equivalence andexercise intensity from EET can be regulated byexercise postures, training purpose, fitness leveland anthropometric features of individuals (likeupper extremity length).

[3]. Gilmar M. Santos Graziela M. S. Tavares; Grazielade Gasperi; Giseli R. Bau, Mechanical evaluation ofthe resistance of elastic bands, Rev. bras.fisioter. São Carlos Nov./Dec. 2009;13(6).

[4]. Martins WR, Carvalho RS, Silva MS, Blasczyk JC,Araújo JA, do Carmo J, Rodacki AL, de Oliveira RJ.Mechanical evaluation of elastic tubes used inphysical therapy, Physiother Theory Pract. 2014Apr;30(3):218-22.

[5]. Thomas M, Müller T, Busse MW, Quantification oftension in Thera-Band and Cando tubing at differentstrains and starting lengths. The Journal of sportsmedicine and physical fitness 2005; 45(2):188-98.

[6]. http://freestyler.net/en/scientific-explanation-of-elastic-resistance.html (Date of reference: 14thJune, 2015).

[7]. http://www.bodylastics.com/pages/elastic-resistance-vs-free-weights-by-jim-stoppani-phd(Date of reference: 14th June, 2015).

[8]. R.Vinodh Rajkumar. Understanding the biomechani-cs of humeral head spinning styles for valid exerciseinnovations in the domain of shoulderstrengthening and rehabilitation, Int J PhysiotherRes 2015; 3(1):868-874.

[9]. Alan E. Mikesky, Robert Topp, Janet K. Wigglesworth,David M. Harsha, Jeffrey E. Edwards Efficacy of ahome-based training program for older adults usingelastic tubing, European Journal of AppliedPhysiology and Occupational Physiology, October1994;69(4):316-320.

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How to cite this article:R.Vinodh Rajkumar. LOAD EQUIVALENCE OF TRANSIENT DEFORMATIONCHARACTERISTICS OF EXERCISE ELASTIC TUBES USED IN PHYSIOTHERAPYREHABILITATION AND FITNESS TRAINING PROGRAMS. Int J Physiother Res2015;3(4):1156-1162. DOI: 10.16965/ijpr.2015.160