Mechanical evaluation of elastic tubes used in physical therapy

Abstract

Mechanical tests revealed different elastic forces for different levels of elongation of each tube. The replication of the results in clinical situations is recommended, so the elastic resistance in clinical routine could be evaluated with more propriety.

Untitled

“…The dynamic determination on ER, just like on the present study, has been performed from the initial-length samples (< 100 mm) shorter than those used in practice (Azevedo et al, 2003;Patterson et al, 2001;Santos et al, 2009;Simoneau et al, 2001). Nevertheless, force versus deformation relationships have been commonly applied instead of the original length (%), which is based on the assumption that the elastic material properties are constant (Patterson et al, 2001;Santos et al, 2009;Simoneau et al, 2001;Thomas et al, 2005). In support of this argument, Patterson et al (2001) and Thomas et al (2005) showed that different lengths could produce similar-force responses with the same relative deformation.…”

“…ER has been mainly quantified by static calibration tests, where the stress-strain relationship is obtained by recording the force response (weights or force transducers) associated with its displacement (deformation) from the initial length (Anderson et al, 2008;Cronin et al, 2003;Mcmaster et al, 2010;Rhea et al, 2009;Shoepe, Ramirez, & Almstedt, 2010;Thomas, Mueller, & Busse, 2005;Wallace et al, 2006). Despite the fact that the tested materials have viscoelastic properties, there is no agreement on the type of adjustment of regression models (linear, quadratic or logarithmic) provided to users (Anderson et al, 2008;Cronin et al, 2003;Mcmaster et al, 2010;Santos et al, 2009;Shoepe et al, 2010;Thomas et al, 2005). Additionally, although dynamic calibration testing demonstrates a non-linear distortion behavior, no regression models for natural rubber devices (NRET) (Patterson et al, 2001;Santos et al, 2009;Simoneau et al, 2001) and alternative synthetic rubbers have been reported (LET) (Azevedo, Benatti, Alves, & Filho, 2003).…”

“…Despite the fact that the tested materials have viscoelastic properties, there is no agreement on the type of adjustment of regression models (linear, quadratic or logarithmic) provided to users (Anderson et al, 2008;Cronin et al, 2003;Mcmaster et al, 2010;Santos et al, 2009;Shoepe et al, 2010;Thomas et al, 2005). Additionally, although dynamic calibration testing demonstrates a non-linear distortion behavior, no regression models for natural rubber devices (NRET) (Patterson et al, 2001;Santos et al, 2009;Simoneau et al, 2001) and alternative synthetic rubbers have been reported (LET) (Azevedo, Benatti, Alves, & Filho, 2003). Patterson et al (2001) found that the response force was not significantly changed after 5000 cycles of load-unload at a constant loading rate of 1800 mm/min (0.5 Hz).…”

“…Higher resistance in the VL is observed at the end of the range of motion, next to the peak of torque curve (Anderson, Sforzo, & Sigg, 2008;Cronin et al, 2003). On the other hand, the eccentric action, as the ability to produce torque decreases, resistance is decreased too (Mcmaster et al, 2010;Rhea et al, 2009;Santos et al, 2009;Wallace et al, 2006). It is therefore presumed that the resistance applied across the range of motion is better adjusted to the force-versus-length curve than the constant load (Biscarini, 2012;Ghigiarelli et al, 2009;Kulig, Andrews, & Hay, 1984).…”

“…Elastic tubing is widely used because of its versatility, practicality and lack of dependence on gravity (Ghigiarelli, Nagle, Gross, Robertson, & Irrgang, 2009;Hughes, Hurd, Jones, & Sprigle, 1999). Latex elastic tubing (LET) and natural rubber elastic tubing (NRET) can provide a considerable range of resistance and are dependent on the thickness and initial length of the material (Mcmaster et al, 2010;Santos, Tavares, Gasperi, & Bau, 2009). For example, the greater the thickness, the greater the resistance at a set initial length, and the smaller the initial length, the greater the resistance imposed on the exercise and strength required to deform the material to the same target length (Biscarini, 2012;Simoneau et al, 2001).…”