Rodrigo Martín-San Agustín

Background Stabilometry, the modified Star Excursion Balance Test (mSEBT) or the Emery balance test (EBT) are reported in the literature to reflect changes after an intervention in monopodal postural stability. Even so, the responsiveness of those tests has not been evaluated after an instability training programme or analysed using multiple statistical indicators of responsiveness. The main aim of this study was to analyse the responsiveness of the stabilometry, mSEBT or EBT. Methods Thirty healthy recreational athletes performed a 4-week programme with three weekly sessions of instability training of the dominant lower limb and were evaluated using stabilometry, mSEBT, and EBT tests. Responsiveness was quantified based on internal and external responsiveness. Results EBT and all parameters in mSEBT for the dominant lower limb showed large internal responsiveness (SRM > 0.8). Furthermore, mSEBT values for the non-dominant lower limb (except anterior displacement) also experienced significant changes with an associated large internal responsiveness. None of the stabilometry platform parameters showed a significant change after the intervention. The ability of the EBT to discriminate between the dominant and non-dominant lower limb ( i.e ., trained vs untrained, respectively) was generally acceptable (AUCs = 0.708). However, none of the parameters of the mSEBT test showed an acceptable AUC. Conclusions EBT showed a positive responsiveness after instability training compared to mSEBT, which only showed internal responsiveness, or stabilometry platform measures, whose none of the parameters could identify these changes.

Context : Calculating the resistance provided by elastic resistance is essential with the aim of adjusting the load and controlling the progression of the exercises in programs using elastic resistance. This study aimed (1) to establish a model of the force elongation for CLX bands; (2) to examine whether these models are altered by different aspects of band elongation: the phase of elongation and shortening (concentric and eccentric phases), the elongation speed, and the initial resting length; and (3) to determine the resistance value for 100% of elongation in each color and to compare it with the values reported by Theraband. Design : Cross‐sectional. Methods : Ten CLX bands of each color were elongated by 2 experienced researchers to establish their elongation force curves in series of 10 repetitions per band using a Smith machine for an anchor, examining whether elongation force models were affected by elongation and shortening phases using one 4-loop CLX band stretched to 100% and at 0.50 m/s, elongation speed stretching two 4-loop CLX bands at 0.50 m/s and at 0.70 m/s, and different starting lengths using 3 CLX bands (2, 3, and 4 loops) stretched at 0.50 m/s. Results : No differences were found in the comparisons between phases, speeds, or different start lengths (mean errors ranged from 0.01 [0.07 N] for the blue band to 2.97 [0.94 N] for the gold band). Our values were higher than the reference values provided by Theraband for all colors, ranging from 2.3% to 33.1%. Conclusions : Our findings show that the values provided by the brand underestimate the resistance provided by CLX bands. To solve this, regression equations are provided so professionals can calculate the resistance of CLX bands based on their elongation. In addition, these models are not influenced by the phase of elongation and shortening, the elongation speed, and the initial resting length.