Minimal important difference of two methods for assessment of quadriceps femoris strength post exercise program in individuals with COPD

Autores da FMUP

• João De Almeida Lopes Da Fonseca

  Autor

Participantes de fora da FMUP

• Santin, L
• Hirata, RP
• Hernandes, NA
• Pitta, F

Unidades de investigação

• Laboratório Associado RISE- Rede de Investigação em Saúde

  

  Investigador

  Fernando Carlos De Landér Schmitt

• Medicina da Comunidade, Informação e Decisão em Saúde

• RISE-Health

  

  Investigador

  Fernando Carlos De Landér Schmitt

Abstract

Background: The assessment of quadriceps femoris (QF) strength is recommended by international guidelines as an outcome of exercise training (ET) programs in patients with chronic obstructive pulmonary disease (COPD). Objectives: To identify the minimal important difference (MID) of two methods for the assessment of improvement of QF strength after a high-intensity ET program in individuals with COPD: 1-repetition maximum (1RM) and maximal voluntary contraction (MVC). Methods: Individuals with moderate to very-severe stable COPD were submitted to high-intensity ET (3 days/week, 36 sessions). Lung function (spirometry), exercise capacity (6-minute walk test [6MWT]) and QF strength (1RM test and MVC by using a strain-gauge) were assessed before and after the ET program. Results: Twenty-one individuals were studied (65 +/- 8 years, BMI 27 +/- 6; FEV1 51 +/- 16%predicted). At the end of the ET program, QF strength improved significantly (10 +/- 4 Nm for MVC and 8 +/- 6 kg for 1RM) (P<0.05 for both). The MID for improvement of the QF strength calculated by distribution-based methods ranged from 9.4 to 16 Nm (between 7.4% and 12.6% increase from baseline) for the MVC and from 2.5 to 3 kg (between 12% and 15% increase from baseline) for the 1RM test. Anchor-based MIDs could not be calculated since there was no correlation between the improvement of QF strength and the improvement of the proposed anchor (6MWT). Conclusions: The MID for improvement of QF strength after a high-intensity ET program in individuals with moderate-to-severe stable COPD ranges between 9.4 and 16 Nm for the MVC assessed with a strain gauge and between 2.5 and 3 kg for the 1RM test. (C) 2022 Elsevier Inc. All rights reserved.

Copyright © 2022 Elsevier Inc. All rights reserved.

Keywords

• Chronic obstructive pulmonary disease; Muscle strength; Lower limb; Exercise