Patients with severe COPD will be recruited from the Respiratory Outpatient Clinic of Kowloon Hospital.

Baseline (pre-intervention) assessment for all recruited subjects will be conducted by one physiotherapist assessor who is blinded to the group allocation of the subject for respiratory function, musculoskeletal performance, physical performance and quality of life. Then, the subjects will be randomly allocated into either the intervention group with therapist-assisted chest wall mobilization exercises, low intensity walking exercise, home exercises and education sessions or the control group with low intensity walking exercise, home exercises and education sessions. The intervention program will last for 6 weeks with 2 sessions / week (i.e. a total of 12 sessions) in accordance to the recommendation for exercise training programs for patients with COPD by the American College of Sports Medicine. Post-program evaluation will be conducted upon program completion at 6 week.

A follow-up session on 3 month after the completion of the program will be carried out to evaluate the cumulative effect of the chest wall mobilization program on respiratory function, musculoskeletal performance, exercise performance and quality of life of the patients.

I. Intervention for Study Group

Structured Chest Wall Mobilization Program

Chest Wall Mobilization Chest wall mobilization is one of the important techniques in chest physical therapy for increasing chest wall mobility and improving ventilation. Either passive or active chest mobilizations help to increase chest wall mobility, flexibility, and thoracic compliance. The mechanism of this technique increases the length of the intercostal muscles and therefore helps in performing effective muscle contraction. It improves the biomechanics of chest movement by enhancing direction of anterior-upward movement of lower costal and downward movement of diaphragm. Maximal relaxed recoiling of the chest wall helps in achieving effective contraction of intercostal muscle. Chest wall mobilization with breathing exercise was showed to effect clinical benefit in chronic lung disease especially COPD with lung hyperinflation or barrel-shaped chest. The technique of chest wall mobilization helps in chest wall flexibility, respiratory muscle function and ventilatory pumping, which helps to reduce dyspnoea and respiratory accessory muscle use.

The chest wall mobilization techniques include:

1. Lateral flexion of chest wall
2. Chest wall extension
3. Lateral gliding of thoracic spine
4. Pectoralis major muscle stretching

There is no standard of practice found on the current studied chest wall mobilization. As good practice for quality and safety assurance, the studied program was evaluated by two independent Physiotherapists expert with post-graduate qualification in Manual Therapy recognised by Physiotherapists Board of Hong Kong Government and the International Federation of Orthopaedic Manipulative Physical Therapists of World Confederation of Physical Therapy. Chest wall mobilization will be performed in a therapist-assisted manner by a single trained and certified American College of Sports Medicine (ACSM) Clinical Exercise Physiologist with more than 10 years' experience working in the speciality with chronic respiratory patients in respiratory medicine.

Subjects will be placed in the sitting position, lying on the back or sidelying position with knees bent to correct the lumbar curve, repositioning of the scapular waist as well as scapular and arm abduction in order to prevent postural compensations. Stretching was performed bilaterally as follows:

1. Lateral flexion of chest wall Patient in supine and lateral position on a foam roller in the infra-axillary region, forearms flexed and hands resting on the occipital region; the therapist used both palmar region hand's to mobilize the ribs in the cranial and caudal direction.
2. Chest wall extension Patient in supine lying on a foam roller in the mid-thoracic region, raise the arm over the head and grasp hold on a fixed wall bar about 10 inches from the surface of the plinth.
3. Lateral gliding of thoracic spine It is a non-thrust transverse vertebral pressure as described by Maitland et al 2005. Patients in prone lying, arms to the side and head in a 'forehead rest position'. Mobilization was applied to the whole thoracic spine. The spinous process of T1 was identified by first locating C6 using the cervical extension method and then counting caudally. The therapist stood at the level of the vertebra to be mobilized on one side of the subject. The pad of the therapist's non-dominant thumb was placed in contact with the lateral aspect of the spinous process of T1, whereas the dominant thumb was placed on the dorsal side of the other thumb. Pressure was applied to the spinous process to produce small amplitude, low velocity oscillations into resistance to the end-range of the vertebra (Grades IV). This procedure was performed for 30 seconds, and then sequentially applied to the next caudal level. The same pattern of application was used on the patient's contralateral side.
4. Pectoralis major stretching Patient in supine position, on the side to be stretched, the patient´s arm was abducted, forearm flexed and hand resting on the occipital region. The displacement was performed with one of the therapist's hands on the upper third of the arm and the other on the lateral region of the upper chest, following the direction of muscle fibres.

The therapist-assisted chest wall mobilization for stretching follow the guidelines of general stretching for skeletal muscles. Static stretching will be performed with the therapist assisted the movement to the available range and hold in that position with the muscle on tension to a point of a stretching sensation. The stretching will be carried out during the expiratory phase with two sets of ten consecutive incursions for each position and a one-minute rest between the series. The holding of the stretching sensation should last for 10 seconds. The intervention will be around 20 minutes in total.

For the participants in the Control group, they will be asked to stay in supine, sidelying and prone positions for around 20 minutes to standardize the treatment time and effect of positioning.

Intervention Group Home Exercise Program For maintenance of the intervention effect and further improvement of chest wall mobility as well as soft tissues elasticity. Self-stretching exercises of trunk extension, rotation, side flexion as well as stretching of the pectoralis major muscle will be taught to the patients as home exercise program. Participants will be asked to perform the home exercise program for 15 minutes, 3 days /week for 6 weeks. An individual exercise log-book with the diagram of the stretching exercises will be given to the subjects to follow the exercises and record down their participation. Weekly telephone contact to participant will be given for motivation and encouragement of program adherence and completing the log books.

II. Intervention for Control Group Subjects in the control group will be asked to maintain their physical activity level as usual. A 15-minute simple stretching exercise on large muscle group will be taught for standardization as a home exercise program. Five stretching exercises for arms and legs will be taught to the patient as a home exercise program. Participants will be asked to perform the home exercise program for 15 minutes, 3 days /week for 6 weeks. An individual exercise log-book with the diagram of the stretching exercises will be given to the subjects to follow the exercises and record down their participation. Same weekly telephone contact to participant will be given for motivation and encouragement of program adherence and completing the log books as that in intervention group.

III. Common Program for Both Groups Standardized Walking Exercise Exercise will be performed on a Gaitkeeper Mobility Research 2000T electronic treadmill (Cortland, New York) set at zero inclination during subject's follow-up visit at Physiotherapy Department of Kowloon Hospital. Each participant will perform 15 minutes supervised walking exercise at a speed maintain with the participant's target heart rate zone of 60-80% Heart Rate Maximum for cardiovascular training. Besides, the oxygen saturation during walking will be kept above 88%. An oximeter will be used to adjust walking speed and monitoring of HR and oxygen saturation.

Standardized Educational Session Three educational sessions (30 minutes for each session) will be included for both intervention group and control group at Physiotherapy Department of Kowloon Hospital. The content of the education include self-management of bronchial hygiene, breathing re-training, relaxation techniques and the importance of exercise. Education pamphlets will be given to both groups of patients.

Inclusion Criteria:

1. COPD patients in out-patient setting: Patients with FEV1/FVC < 0.70 and

GOLD stage III ( Severe) :

30% < or = FEV1 < 50% predicted

*GOLD - Global Initiative for Chronic Obstructive Lung Disease

2. Ambulatory

3. Able to communicate

4. Competent to give written consent

Exclusion Criteria:

1. Contraindications to chest wall mobilization:

   • Severe and unstable rib fracture
   • Metastasis bone cancer
   • Tuberculosis spondylitis
   • Severe osteoporosis

2. Hospitalization due to acute exacerbation of COPD in recent 1 month

3. Current Smoker