Facial Tactile Stimulation and Hamstring Flexibility
Condition: Hamstring Flexibility
Study type: Interventional

Summary: 
      Inhibition of the sub-occipital muscle group is shown to increase the elasticity of Hamstring
      muscles. Reversely, stretching of the hamstring muscles is shown to change the pressure pain
      thresholds over the masseter and upper trapezius muscles. There appears to be a functional
      link between the neuromuscular system of the head and neck and lower extremities. The present
      study aimed to investigate the effect of tactile stimulation of facial skin on hamstring
      length in healthy young males. A total of sixty-six participants participated in the study.
      Hamstring length was measured by the 'Sit and reach' test in long sitting and 'Toe touch'
      test in standing position before and after two minutes of facial tactile stimulation in the
      experimental group and rest in the control group.
    

Detailed description: 
      Sixty-six young healthy males in the age range 20-30 years participated in the study. They
      were free of any musculoskeletal conditions that would affect their performance during the
      test procedures. Subjects were randomly divided into two groups, the experimental group (EG)
      and control CG) groups. After each subject was briefed about the objectives and procedure of
      the experiment, written informed consent was obtained. The study fully complied with the
      ethical standards for human research of our university review board.

      The 'Sit and Reach' (SR) test in long sitting and the 'Toe touch' (TT) test in standing were
      performed according to previously described protocols. Before the start of each testing
      session of flexibility tests (SR and TT), subjects were asked to perform about 3-5 minutes of
      warm-up and standardized static stretching exercises focused on the lower back and hamstring
      muscles.

      For the SR test, a strong cubic wooden box of 35 cm was placed against the wall and each
      subject sat on the floor mat in a long sitting position. The knees were in full extension and
      the soles of the shoeless feet in neutral ankle position were placed against the box.
      Subjects were asked to slowly reach forward towards the toes as far as possible while keeping
      elbows and fingers fully extended, with palms facing down. The subjects had to maintain this
      position for about five seconds. The distance (in centimeters) between the tips of the middle
      finger and a reference point on the wooden box was noted.

      For the TT test, subjects had to stand upright on the wooden box with feet at hip-width apart
      and were instructed to bend slowly to reach towards the toes as far as possible while keeping
      the knees, elbows, and fingers fully extended, with palms facing backward. The subjects had
      to maintain this position for about five seconds. Again, the distance (in centimeters)
      between the tips of the middle finger and a reference point on the floor was noted.

      For both the SR and the TT tests, the calculated mean recorded distance between the tips of
      the middle fingers and the reference point during three trials with two-minute rest intervals
      in-between was used as a reference value for each subject for subsequent analyzes. These mean
      values were termed Pretest-SR and Pretest TT, respectively. Following the baseline assessment
      value of the SR and TT tests, each subject of CG or EG underwent three additional trials for
      each test, with a two-minute interval in between the trials. SR and TT tests were performed
      randomly without any specific order for both groups of subjects at the same time of day and
      room temperature. During the two-minute interval, the CG subjects spent their time resting in
      the supine position with closed eyes, while the EG subjects received tactile stimulation on
      the facial skin in the supine position with closed eyes. The tactile stimulation to the
      facial skin of the EG subjects was given by one of the authors and consisted of random
      strokes similar to a paintbrush around the face with soft tissue paper for two minutes.

      For each subject of the CG and EG, the mean distance values between the tips of the middle
      fingers and the reference point during three trials during the SR and TT tests were
      calculated, respectively. These mean values were termed Post-test-SR and Post-test-TT,
      respectively. For all subjects of both the CG and EG, the difference between the Post-test-SR
      and Pre-test-SR; and Pre-test-TT and Pre-test-TT mean values were calculated. A greater
      difference between the Post-test-SR and Pre-test-SR; and the Post-test-TT and Pre-test-TT
      mean values were considered as increased flexibility of the hamstring muscles.
    

Intervention name(s): Facial tactile stimulation
Intervention type(s): Other
Intervention description(s): Tactile stimulation was given around the face with soft tissue paper for two minutes.
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Two arms parallel (Experimental and control group) design.
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Other
Keywords: Facial skin; hamstring muscle flexibility; tactile Stimulation