Ultrasonography comparison of diaphragm thickness and excursion between athletes with and without lumbopelvic pain

Highlights

• Diaphragm thickness and excursion were compared between athletes with and without lumbopelvic pain by ultrasound imaging.

• Athletes who suffered from LPP presented a reduced diaphragm thickness compared to healthy matched-paired athletes.

• Diaphragm reeducation care in athletes could improve the intervention related to athletic performance, prevention and rehabilitation.

Abstract

Objective

The aim of this study was to compare diaphragm thickness and excursion between athletes with and without lumbopelvic pain (LPP) by trans-costal and trans-hepatic rehabilitative ultrasound imaging (RUSI), respectively.

Design

A case-control study.

Setting

Amateur and semiprofessional athletes teams.

Participants

Forty matched-paired athletes with LPP (n = 20; LPP case group) and without LPP (n = 20; Healthy control group) were recruited.

Main outcome measures

Diaphragm thickness and excursion (cm) were assessed during relaxed respiratory activity (maximum inspiration–T^ins, expiration–T^exp and difference–T^ins-exp) by trans-costal and trans-hepatic rehabilitative ultrasound imaging (RUSI), respectively.

Results

Statistically significant differences (P < .05) with an effect size from moderate to large (d = 0.63–1.07) were shown for bilateral diaphragm thickness reductions at T^ins and thickness difference at T^ins-T^exp of the right hemi-diaphragm for athletes with LPP compared to healthy athletes.

Conclusions

Athletes who suffered from LPP presented a reduced diaphragm thickness compared to healthy matched-paired athletes. Therefore, these novel findings may suggest that diaphragm reeducation could be a main focus of intervention related to athletic performance, prevention and rehabilitation. Nevertheless, these findings should be considered with caution due to the possible influence of the RUSI measurement errors of the diaphragm activation during normal breathing.

Introduction

Lumbopelvic pain (LPP) may be considered as a common compliant in athletes (Fett, Trompeter, & Platen, 2017). Indeed, athletes who suffered from LPP have shown an altered spine stabilization function associated to the loss of trunk deep muscles anticipatory contraction (P. W. Hodges & Richardson, 1996; Panjabi, 2003; Swain, Bradshaw, Whyte, & Ekegren, 2017). Concretely, the term “core” has been widely used in order to refer to a belt-like tension to the trunk provided by the automatic activation of these deep muscles (Kibler, Press, & Sciascia, 2006). Thus, the “core” stability is essential to perform trunk and limb movements in a correct way, especially in athletes (Kibler et al., 2006).

Regarding the deep muscular stabilizers, the transversus abdominis and internal oblique, multifidus, diaphragm and pelvic floor muscles comprised the “core” that provides an adequate motor control and stability to the spine of athletes (Huxel Bliven & Anderson, 2013). Several valid and reliable tools were used to evaluate static and dynamic muscular conditions, such as electromyography (EMG), magnetic resonance imaging (MRI) and rehabilitative ultrasound imaging (RUSI), which may be considered as a conservative, non-invasive, non-expensive, valid and reliable tool for measuring the thickness at rest and during contraction of the deep trunk muscles (J. Hides et al., 2006; P. Hodges, Pengel, Herbert, & Gandevia, 2003; Potter, Cairns, & Stokes, 2012; Teyhen, 2007).

Thus, RUSI has been widely applied for the static and dynamic evaluation of the “core” deep trunk muscles in athletes and LPP, such as the abdominal wall muscles (Ferreira, Ferreira, & Hodges, 2004; Gala-Alarcón et al., 2018; Paris-Alemany et al., 2018; Paungmali, Joseph, Sitilertpisan, Pirunsan, & Uthaikhup, 2017; Romero-Morales et al., 2018; Sitilertpisan et al., 2011; Teyhen et al., 2007; Whittaker, Warner, & Stokes, 2013), multifidus (J. A. Hides & Stanton, 2014; J. A. Hides, Stanton, McMahon, Sims, & Richardson, 2008; J. A. Hides, Stanton, Mendis, Franettovich Smith, & Sexton, 2014; Mahdavie, Rezasoltani, & Simorgh, 2017; Stokes, Hides, Elliott, Kiesel, & Hodges, 2007; Wachi et al., 2017) and pelvic floor muscles (J. A. Hides et al., 2008; Painter, Ogle, & Teyhen, 2007; Thompson, O'Sullivan, Briffa, Neumann, & Court, 2005; Whittaker, Thompson, Teyhen, & Hodges, 2007). Nevertheless, there is a lack of research regarding the diaphragm morphology and muscular activity in athletes who suffer from LPP (Brown et al., 2013; Harper et al., 2013; Terada, Kosik, McCann, & Gribble, 2016; Testa et al., 2011).

Indeed, B-mode RUSI has shown to be valid and reliable in order to evaluate trans-costal and trans-hepatic diaphragm morphology and activity during breathing (Goligher et al., 2015; Harper et al., 2013; Testa et al., 2011). Recently, prior MRI studies showed a thinner diaphragm with reduced respiratory excursion and worse muscle cooperation in subjects with LPP (Vostatek, Novák, Rychnovský, & Rychnovská, 2013). Greater fatigability (Janssens et al., 2013), smaller excursion and higher position of the diaphragm were reported in patients with LPP (Kolář et al., 2012). Nevertheless, RUSI technique has shown to use a portable and cheaper tool than MRI with a rising use in the physical therapy field (Fernández Carnero et al., 2019; Fernández-Carnero, Calvo-Lobo, Garrido-Marín, & Arias-Buría, 2018). Considering specifically the physical therapy in sport, the deep muscular stabilizers of the spine of athletes with LPP may present an impaired “core” motor control and stability (Huxel Bliven & Anderson, 2013). Despite prior RUSI studies in athletic populations with LPP have shown morphological and contractile alterations in muscles of the abdominal wall (Ferreira et al., 2004; Gala-Alarcón et al., 2018; Paris-Alemany et al., 2018; Paungmali et al., 2017; Romero-Morales et al., 2018; Sitilertpisan et al., 2011; Teyhen et al., 2007; Whittaker et al., 2013), lumbar region (J. A. Hides & Stanton, 2014; J. A. Hides et al., 2008, 2014; Mahdavie et al., 2017; Stokes et al., 2007; Wachi et al., 2017) and pelvic floor (J. A. Hides et al., 2008; Painter et al., 2007; Thompson et al., 2005; Whittaker et al., 2007), there is a lack of research addressing the diaphragm thickness and excursion during normal breathing by RUSI in athletes with LPP with respect to healthy matched-paired controls (Brown et al., 2013; Harper et al., 2013; Terada et al., 2016; Testa et al., 2011).

In addition, the effects of diaphragm training on lumbar stabilizer muscles have shown an improvement of the segmental stability in patients with LPP (Finta, Nagy, & Bender, 2018), and the pelvic floor and diaphragm have been proposed as synergists muscles with transversus abdominis, being responsible for increasing and maintaining the intraabdominal pressure during postural tasks (P. W. Hodges, Butler, McKenzie, & Gandevia, 1997). The main role of diaphragm in trunk stabilization has been investigated for more than 50 years, although the exact mechanisms still remain poorly understood (Kolar et al., 2010). Patients with LPP appeared to show an abnormal position as well as a steeper slope of the diaphragm muscle, which may be considered as a contributing cause of this condition (Kolář et al., 2012). Indeed, this deep muscular stabilizer function of the diaphragm may play a main role in the spine of athletes with LPP (Huxel Bliven & Anderson, 2013). We hypothesized that athletes who suffered from LPP may show reduced diaphragm thickness and excursion due to the key role of the diaphragm muscle as a deep muscular stabilizer of the “core” in the athletic population and the diaphragm thickness was related to neuromuscular alterations in the lumbo-pelvic region being mainly considered a postural stabilizer more than a respiratory muscle according to force–length relationship modifications (Celli, 1989; Hruska, 1997; Huxel Bliven & Anderson, 2013; Terada et al., 2016). Therefore, the aim of this study was to compare diaphragm thickness and excursion between athletes with and without LPP by trans-costal and trans-hepatic RUSI, respectively.