Assessment of the Acute Effect of Cycling Practice in Lumbar and Thigh Muscles

Introduction: Cycling represents a very important level of practice, being among the most practiced sports in Spain. As in any other sport discipline, its practice is associated with the appearance of overloads and sports injuries. Specifically, the 2 most affected areas are the lumbar and knee areas, with an annual prevalence of 58% and 36%, respectively. There is no clear hypothesis to explain the low back pain associated with the practice of cycling, but several authors agree that it may be due to holding an inverted posture of the rachis and the characteristics associated with this sport: long duration, static posture, high intensities, vibrations generated by the terrain, and so forth. The project proposes to analyze the acute effect of a long-lasting bicycle trip (3 hours) on the muscles involved in low back and knee pain, see, lumbar paravertebral, quadriceps and hamstrings, by means of tensiomyography (TMG). Objectives: the main objective of this study is to evaluate the behavior of the mechanical characteristics of the lower back and thigh muscles, by means of tensiomyography, in amateur cyclists after an acute effort on road and mountain bikes, and to study their possible relationship with low back pain (LBP).

A crossover randomized controlled trial. The participation in the study requires only 2 assistances to the data takings that will be developed in the training laboratory of the Faculty of Sciences of Physical Activity and Sport of the European University. 40 amateur cyclists will be randomly assigned to carry out each (2) conditions of intervention: a road bike time trial (CA) and a mountain bike time trial (MT) separated by 7 days washout. *Randomization marks the order in which participants are subjected to an intervention condition or other. These sessions will begin with an initial assessment, which will be carried out: an anthropometric assessment (height and weight), followed to an evaluation of the tensiomyographic variable maximal radial displacement (Dm) over the thigh muscles: vastus medialis (VM), rectus femoris (RF), vastus lateralis (VL), biceps femoris (BF), and erector spinae (EE) at the lumbar level, before and after an acute effort (> 3 hours) in CA and MT bicycle. Respect to pain assessment, it will be measured the intensity pain perception on the lumbar region (LBPP) by using a 0 to 10 numeric pain-rating scale; the pressure pain threshold (PPT) with a manual mechanical algometer; and the functional disability caused by LBP through the Roland-Morris Questionnaire (RMQ).

A cross-over study with a single group (n = 40) of amateur cyclists subjected to each 2 different intervention conditions: a road bike time trial (CA) and a mountain bike time trial (MT).

First Intervention (3 hours: Road cycling), followed by a 7 days washout, and the second Intervention (3 hours: Mountain Biking).

First Intervention (3 hours: Mountain Biking), followed by a 7 days washout, and the second Intervention (3 hours: Road cycling).

The road itinerary is a mixed route profile of 90 km, an elevation gain of 900 m, with mixed sections, flat, uphill and down over roads with little traffic.

The mountain itinerary, is a mixed route of 55 km, an elevation gain of 600 m, with sections of wide tracks and trails, flat, uphill and down, with a medium technical difficulty.

This variable records the intensity pain perceived on the lumbar region (LBPP) by using a 0 to 10 numeric pain-rating scale (NPRS). This is an 11-point scale ranging from 0 (no pain) to 10 (worst imaginable pain). The LBPP was measured before and after completing each time trial.

The variable Dm is given by the radial displacement of the muscular belly in a transverse plane, expressed in milimeters (mm) and depends on muscle tone or stiffness. A low Dm is related to a high muscle tone or an excess of stiffness, while a high Dm value indicates a lack of muscle tone or stiffness defect.

Measured from 0 to 10kg/cm2 with a manual mechanical algometer (FDK/FDN, Wagner Instruments, 1217 Greenwich, CT 06836), which has bilaterally shown an excellent reliability, reproducibility, and sensitivity on the lumbar erector spinae muscles.

The functional disability caused by LBP through the Roland-Morris Questionnaire (RMQ). The score ranges from 0 to 24, with 0 indicating no disability and 24 maximum disability.

Inclusion Criteria: Be a man Aged between 18 and 55 years. Minimum experience in the practice of cycling over 3 years Accumulate at least 200 hours of training each year. Not having received specific treatment in the musculature evaluated in the last 4 weeks, or being subjected to any treatment at present. No pathology diagnosed in the anatomical regions interested in the study (lumbar, thigh, hip or knee). Sign the informed consent. Exclusion criteria Have had strenuous exercise in the previous 48 hours Having taken energy drinks in the last 48 hours Have ingested alcohol or caffeine in the 3 hours prior to taking data.