Effect of Volume Training on Back Endurance
Condition: Back Pain
MeSH terms: Back Pain
Study type: Interventional

Summary: 
      The fatigue of the trunk extensor muscles is often reported in people with the chronic low
      back pain (LBP). Evidences have showed that the strengthening muscular by the training of the
      lumbar spinal muscles is efficient to decrease the pain and disability symptoms of patients
      with the chronic LBP. Also, some studies have reported improve of the strength and endurance
      of the back muscles from of this type of training muscular. However, the exercise
      prescription for the trunk extensor muscles during the training is still not clear in the
      literature. In fact, no study has showed any differences between one and three sets of
      specific lumbar exercise with regard to better prescription of training in healthy subjects
      (e.g; preventive action) as well as in LBP subjects (e.g; intervention action).
    

Detailed description: 
      The purpose of this study is to compare an endurance trunk extensor training using one and
      three sets of exercise repetition on gains of strength and endurance muscular in healthy
      subjects.

      Forty-two healthy voluntaries (from 18 to 35 years) of both the sexes will participate of
      this study. All participants will sign an informed consent form approved by the North of
      Parana University Ethics Committee for Research on Human Subjects. The sample will be
      randomized in three groups by the allocation from printed cards sequentially numbered in
      opaque envelopes: (G1, n=14) the participants will perform three sets of 15-20 repetitions of
      the trunk extensor exercise on a roman chair machine with the hips at 45 degrees relative to
      horizontal; performing trunk flexion-extension cycles for a total of 4 seconds (2 s
      concentric and 2 s eccentric contraction); (G2) the participants will perform only one set of
      15-20 repetitions of the trunk extensor exercise on a roman chair machine with the hips at 45
      degrees relative to horizontal; performing also trunk flexion-extension cycles for a total of
      4 seconds (2 s concentric and 2 s eccentric); and (G3) the participants will be the control
      group, which not participating of any exercise program in any time during the study. A total
      of 10 weeks of training will be performed in the study, by 2 x week with the progression of
      load volume (increase the load if the total repetition of 20 is reached).

      Before and after the lumbar training, all participants will be assessed by the endurance
      muscular (Isometric Sorensen test using time-limit, Dynamic endurance using the number of
      repetition, Borg fatigue perception scale and EMG surface of trunk extensor muscles by
      computation of median frequency fatigue estimate); and by the strength muscular (back
      isometric maximal voluntary contraction using a dynamometer on a roman chair). An evaluator
      trained will perform all testing assessment, in baseline time and after weeks of training.
      The evaluator will be blinded with regard the groups on assessment. Also, an exercise
      professional of sport will be responsible by exercise prescription to prescript the training
      at the Fitness center in the UNOPAR University; This professional will be also blinded to the
      groups.

      An ANOVA two-way to compare the effects in the three groups (G1, G2, and G3) and the two
      times session-1: baseline and session-2: after 10 weeks); and the effects of interaction
      (Groups X Times) also will be tested. When necessary a Tukey post hoc analysis will be
      performed to localize the differences on the three groups. The effect size on each group will
      be calculated to determine the rate of changes from the training intervention.
    

Intervention name(s): Exercise
Intervention type(s): Other
Intervention description(s): The groups will perform the trunk extensor exercise on a roman chair by 2 x week, for a total of 10 weeks of training (20 sessions). The load will be progressive and tested to each 14 days with regard to the number of repetition reached by the participant. The exercise is safe and will be supervised by a health sport professional.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment
Keywords: Exercise; Training; Low back Pain; Physical Therapy