Effect of a Novel Stretching Technique on Shoulder Range of Motion and Voluntary Contraction in Overhead Athletes With Glenohumeral Internal Rotation Deficits "GIRD"

To examine and compare the effect of a novel stretching technique and traditional stretching
on glenohumeral range of motion, strength, maximum voluntary contraction, pain, and subject
satisfaction in overhead athletes with glenohumeral internal rotation deficits through a
randomized clinical study. The investigators hypothesize that this type of novel intervention
will help subjects with GIRD to restore range of motion, experience less pain and maintain
the strength and motor unit recruitment following the novel intervention. This will help us
to assess the potential beneficial effect of such intervention and to fill the gap in
knowledge and help health care professionals to adequately select the right treatment
modality.

Independent Variable

1. Type of Intervention:

- Traditional Stretching (Modified Sleep Stretch). VS

- Novel Stretching (Active Shoulder Internal Rotation while Bridging) 2. Time

- Pre VS post intervention Dependent Variables

1. Glenohumeral internal rotation ROM

2. Maximal glenohumeral external rotation isometric strength.

3. Mean motor unit recruitment (EMG) of the glenohumeral external rotator
(infraspinatus) and internal rotators (pectoralis major and latissumus dorsi)

4. Pain

5. Subject satisfaction

Instrumentation :

1. Glenohumeral internal & external rotation ROM: will be measured at baseline and at week
four-post intervention for all participants. We will use the digital inclinometer.
Research by (Kolber et al.,2011 ) showed this instrument to be reliable with an
intra-rater ICC =0.87 and inter-rater ICC =0.93

2. Electronic push/pull dynamometer: At the end feel ROM, and before ROM is measured, the
therapist will apply the same amount of pressure to all subjects to ensure reliable/
valid ROM measurements.

3. Maximal Glenohumeral External Rotation Isometric Strength will be measured using a
MicroFET2 handheld digital dynamometer. This device was shown to be reliable with an
intra-rater ICC =0.85 and inter-rater ICC =0.85.

4. Maximum Voluntary Contraction: will be measured using a 44 Delsys Bagnoli portable
surface electromyography (sEMG) system.

5. Pain: will be measured using the Numeric Pain Rating Scale (NPRS). The NPRS has shown to
have a valid, reliable and appropriate for use in clinical practice

Procedures:

All participants will perform the static stretching (SS) conditions by themselves. The two
stretching techniques will be home-based program.

Inclusion Criteria:

- Participants must be between the age of 18 and 45.

- Perform overhead sports activities in the past 3 months.

- Participants are required to display ≥ 20° less glenohumeral internal rotation ROM in
their dominant shoulder compare to the non- dominate shoulder.

- Participants will be included with or without pain during shoulder activities.

Exclusion Criteria:

- Will exclude participants who are still recovering from previous surgery of the
shoulder and elbow complex in the past 3 months, and currently receiving medical
intervention for the shoulder.