Relative Stiffness of Lumbar Spine and Hamstrings Muscle Stretching
Condition: Back Pain; Instability Lumbar Spine; Muscle Tightness
MeSH terms: Back Pain
Study type: Interventional

Summary: 
      The purpose of this study is to investigate the effect of lumbopelvic stabilization on
      hamstrings muscle stretching in individuals with history of low back pain suspected to have a
      clinical lumbar instability.
    

Detailed description: 
      The participants between the age of 20 and 40 years with history of low back pain will be
      recruited from Mahidol University using a poster posted at Faculty of Physical Therapy. All
      participants will be explained the purposes, advantages, disadvantages and procedures of the
      study by the researcher. The participant will be asked to sign an informed consent if the
      participants are willing to participate in this study.

      After obtaining the written informed consent, the researcher, who works in musculoskeletal
      system including low back pain for 7 years and has received 3 training sessions on clinical
      observation of aberrant movement, will perform 2 clinical tests including clinical
      observation of aberrant movement patterns and passive straight leg raising test to identify
      clinical lumbar instability, and measure hamstrings muscle length using clinical motion
      analysis system. The researcher will also screen for exclusion criteria using a check list.

      For those who are qualified for the study, the participants will be asked to fill out the
      demographic data and physical activity questionnaire. The researcher will perform additional
      clinical examination including modified Thomas test, back extensor muscle strength test
      assessed by a handheld dynamometer, Trendelenburg's test and lumbar stability test. After
      clinical tests, lumbopelvic, pelvic, and lumbar range of motions during an active forward
      bend task will be measured by using the clinical motion analysis system. These outcome
      measures will be assessed for baseline (Pre-1). After baseline data collection, the
      participants will be divided into 2 groups; lumbopelvic stiffening group (LS) or lumbopelvic
      relaxing group (LR) by randomly generated code in a concealed envelope.

      The participants in LS group will stretch the hamstrings muscle in standing position with
      lumbopelvic stabilization. Fifteen percent of the body weight will be used to standardize
      stretching force. This force will be controlled by visual feedback from load cell. During
      stretching protocol, the participants will be instructed to face the hydraulic table with the
      hips square, maintain trunk straight up and look straight ahead. Researcher commands "during
      adjusting the bed up, please tense the lower back rigid". After that, hydraulic bed will be
      lifted up until force reaches 15 percent of the body weight. Participant will perform 30
      seconds/repetition for 4 repetitions with 15 seconds rest between repetitions. To ensure that
      participant correctly performs lumbopelvic stabilization, the researcher will palpate at ASIS
      and iliac crest to check pelvic motion during hamstrings muscle stretching. Pelvic motion
      indicates loss of lumbopelvic stabilization. Participant will be asked to re-perform another
      repetition. Our protocol is based on a previous study by DePino et al., 2000. Participant
      will perform 30 seconds/repetition for 4 repetitions with 15 seconds rest between
      repetitions. The investigators use 30 seconds because a systematic review suggests that 30
      seconds is the most effective dose for hamstrings muscle stretching.

      For the participants in LR group, the participants will be instructed to face the hydraulic
      table with the hips square, maintain trunk straight up and look straight ahead. The
      researcher commands "During adjusting the bed up, please relax the lower back". The hydraulic
      bed will be lifted up until force reaches 15 percent of the body weight. Participant will
      perform 30 seconds/repetition for 4 repetitions with 15 seconds rest between repetitions.

      After the intervention, the participants will be reassessed for hamstrings muscle length
      test, lumbar motion, pelvic motion and total lumbopelvic motion (Post-1). Because this study
      uses a cross-over study design, participants will be asked to maintain the usual physical
      activity for 2 days as a wash-out period. Then, the participants will be re-assessed for
      baseline data (Pre-2), and cross-over to another stretching group (LS changes to LR, while LR
      changes to LS). After completion of intervention, the participants will be re-assessed for
      post-intervention (Post-2). These to determine the effectiveness of lumbopelvic stabilization
      during hamstrings stretching in standing.
    

Intervention name(s): Lumbopelvic stiffening technique; Lumbopelvic relaxing technique
Intervention type(s): Other; Other
Intervention description(s): Participants will stretch their hamstrings muscle in standing position with lumbopelvic stiffening technique. Fifteen percent of the body weight will be used to standardize stretching force. During stretching protocol, the participants will be instructed to face the hydraulic table with their hips square, maintain trunk straight up and look straight ahead. Researcher commands "during adjusting the bed up, please tense your back rigid". After that, hydraulic bed will be lifted up until force reaches 15 percent of the body weight. Participant will perform 30 seconds/repetition for 4 repetitions with 15 seconds rest between repetitions.; Participants will be instructed to face the hydraulic table with their hips square, maintain trunk straight up and look straight ahead. The researcher commands "During adjusting the bed up, please relax your back". The hydraulic bed will be lifted up until force reaches 15 percent of the body weight. Participant will perform 30 seconds/repetition for 4 repetitions with 15 seconds rest between repetitions.
Allocation: Randomized
Intervention model: Crossover Assignment
Intervention model description: Participants will be randomly assigned to either stretching exercise with lumbopelvic stiffening technique or lumbopelvic relaxing technique. They will be provided a 2-day wash-out period. Then, participants will cross-over to another technique.
Masking: Double (Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: History of low back pain; Clinical lumbar instability; Stretching exercise