Combined Effect of Thoracic Spine Manipulation with Jandas Approach on Electromyographic Activity in Subjects with Upper Cross Syndrome:A Randomized Clinical Trial

BRIEF RESUME OF INTENDED WORK

INTRODUCTION

Upper Cross Syndrome (UCS) is a common postural dysfunction resulting from muscular imbalance in the cervicothoracic region, typically seen in individuals engaged in prolonged sitting, computer use, or forward head posture activities.[ 1]

It is characterized by tightness of the upper trapezius, levator scapulae, and pectoralis major and minor, along with weakness of the deep cervical neck flexors, lower trapezius, and serratus anterior.[2]

This pattern of imbalance leads to forward head posture, rounded shoulders, and increased thoracic kyphosis, which can alter scapulothoracic and glenohumeral kinematics and impair shoulder and upper-limb function.[3]

Thoracic spine manipulation (TSM) is a high-velocity, low-amplitude (HVLA) technique aimed at restoring segmental mobility, reducing stiffness, and modulating neural excitability through both mechanical and neurophysiological effects.[4]

It is proposed that spinal manipulation can influence motor neuron excitability and cortical drive, thereby enhancing muscle performance.[5]

Hypomobility of the thoracic spine contributes to compensatory cervical loading and muscular overactivity, further aggravating Upper Cross Syndrome.[5]

Electromyography (EMG) provides an objective measure of muscle activation and can assess neuromuscular changes following interventions.[6]

 NEED FOR THE STUDY

Upper Cross Syndrome (UCS) is increasingly prevalent due to sedentary lifestyles and excessive screen use, leading to muscular imbalance and postural dysfunction that negatively affect upper-limb function and strength.[1]

UCS is associated with altered scapulothoracic rhythm and inhibited activation of stabilizing muscles, which may predispose individuals to shoulder pain and movement inefficiency.[5]

Thoracic hypomobility has been linked with cervical and shoulder dysfunction, suggesting that improving thoracic motion can restore normal neuromuscular coordination.[6]

Thoracic spine manipulation (TSM) produces both mechanical and neurophysiological effects, including enhanced motor neuron excitability and improved corticospinal drive.[2]

Evidence from previous studies shows that thoracic manipulation improves shoulder range of motion, but most of these studies are conducted on shoulder impingement , neck disability  or healthy individuals, not UCS populations.[2]

To the best of our knowledge there are no studies which have explored the EMG activity of thoracic manipulation with Janda’s Approach specifically in individuals with Upper Cross Syndrome.

Thoracic spine manipulation  enhances activation of inhibited postural stabilizers through neurophysiological mechanisms, but its combined influence with Janda-based exercises on EMG outcomes remains underexplored.

This study seeks to bridge this gap by objectively evaluating electromyographic activity following a combined intervention of thoracic spine manipulation and conventional strengthening in UCS

AIMS OF THE STUDY

To compare the combined effects of thoracic spine manipulation with Janda’s Approach on electromyographic activity in patients with upper cross syndrome.

OBJECTIVES OF THE STUDY

To determine the combined effect of thoracic spine manipulation with Janda’s Approach on EMG activity of Upper Trapezius, Pectoralis Major, Lower Trapezius and Serratus Anterior

HYPOTHESIS

q NULL HYPOTHESIS –

N0 - There is no difference in change in EMG activity between the group receiving thoracic spine manipulation + Janda’s approach and the control group.

 q ALTERNATIVE HYPOTHESIS –

A0 - There is a difference in change in EMG activity between the two groups. (i.e. it    should show decreased EMG activity in tight muscles- Upper Trapezius, Pectoralis Major and increased EMG activity in weak muscles-Lower Trapezius, Serratus Anterior).

REVIEW OF LITERATURE:

1.     The study performed by Chang MC et al in 2023, demonstrated that multimodal rehabilitation leads to significant reductions in pain and postural muscle imbalance in upper crossed syndrome. Manual therapy, particularly cervical and thoracic mobilization/manipulation, combined with pectoralis, upper trapezius, and levator scapulae stretching, improved segmental mobility and posture. Strengthening of deep cervical flexors and scapular stabilizers enhanced endurance and corrected forward head and rounded shoulder alignment. The review concludes that integrated exercise programs with patient education support long-term functional recovery [1]

2.     A study performed by Chaudhuri et al. in the year 2024 reported through a Delphi consensus that a validated conceptual framework for Upper Cross Syndrome (UCS) includes key postural, neuromuscular, and movement-pattern dysfunctions. Experts agreed on forward head posture, rounded shoulders, thoracic kyphosis, and muscle activation imbalance as defining characteristics. The study highlighted the importance of standardized assessment components involving deep neck flexor weakness and scapular stabilizer dysfunction. The framework supports evidence-guided clinical decision-making and development of targeted rehabilitation protocols for UCS. [2]

3.     In a recent study performed by Bayattork et al. in the year 2020 proposed a parallel-group RCT protocol indicating that a comprehensive corrective exercise program targeting muscular imbalance is expected to improve postural alignment and normalize muscle activation in men with upper crossed syndrome. The intervention emphasizes scapular stabilizer and deep neck flexor training combined with stretching of tight anterior chain muscles, which prior evidence supports for posture correction.[3]

4.     In a study performed by Walser et al. in the year 2009 , reported that thoracic spine manipulation (TSM) produces significant improvements in pain, spinal mobility, and functional outcomes across multiple musculoskeletal conditions. The meta-analysis highlighted positive short-term effects on mechanical neck and shoulder disorders and movement dysfunctions. TSM was found to be a safe and clinically beneficial adjunct when combined with therapeutic exercise or multimodal physiotherapy. The review supports that manual manipulation of the thoracic spine enhances recovery by improving regional biomechanics and reducing musculoskeletal pain. [4]

5.     A study performed by Haavik et al. demonstrated that spine manipulation significantly increases cortical motor drive to both upper and lower limb muscles, indicating neuroplastic effects beyond local biomechanics. Using EMG and neurophysiological measures, the study showed enhanced corticospinal excitability and improved sensorimotor integration after spinal manipulation. Findings suggest that manual therapy can positively influence brain-muscle communication and motor control. The research supports the role of manipulation as a neurologically active intervention for improving muscle activation patterns in rehabilitation.[5]

6.     A recent study performed by Arshadi et al. in 2019 proved that an 8-week selective corrective exercise program significantly increased EMG activation of deep neck flexors and scapular stabilizers while reducing overactivity of upper trapezius and levator scapulae in individuals with upper crossed syndrome. Targeted muscle training improved neuromuscular balance and postural control, supporting its effectiveness as a structured rehabilitation approach. Findings reinforce that corrective exercises positively modify dysfunctional muscle activation patterns relevant to UCS recovery.[6]

7.     In a study performed by Robles-Pérez et al. in the year 2019  reported that thoracic manual therapy significantly improves pain and reduces disability in subacromial pain syndrome, both with and without exercise, showing added value of manual techniques. When combined with exercise, outcomes in shoulder function and patient-reported disability further improved, indicating a strong multimodal benefit. The study supports thoracic manual therapy as a safe, effective intervention for enhancing functional recovery.[7]

8.     In a study  performed by Delgado-Gil et al. found that mobilization with movement (MWM) significantly reduced shoulder pain and improved active range of motion in patients with unilateral shoulder impingement after intervention. The study reported notable gains in flexion and abduction mobility, enhancing functional movement. MWM was shown to be a safe and effective manual therapy technique for joint and movement restoration. Results support immediate clinical benefits in pain relief and movement performance for shoulder rehabilitation.[8]

9.     In this study which was performed by Izraelski et al. in the year 2012 whivh was  based on the Janda approach emphasized that muscle imbalance assessment must integrate postural analysis, movement testing, and targeted manual + exercise therapy to restore functional stabilization. The approach showed positive clinical effects on correcting forward head posture, rounded shoulders, and altered muscle activation, supporting individualized corrective rehabilitation. Findings highlight that pattern-based exercise and stretching are key to reversing chronic postural dysfunction. [10]

10.  In this study performed by Merletti et al. provided evidence that non-invasive EMG is a reliable method to quantify muscle activation, fatigue, and motor unit behaviour, enhancing objective clinical evaluation. The book supports accurate analysis of neuromuscular recruitment patterns relevant to posture and movement disorders. It reinforces that surface EMG is essential for evidence-based rehabilitation research and clinical biofeedback training. [11]

11.  In a study performed by Hermens et al. in the year 2000 developed standardized recommendations showing that proper SEMG sensor placement ensures high signal quality and reduces cross-talk, improving measurement validity. Guidelines support consistent scapular and cervical muscle monitoring when protocols follow anatomical alignment. The findings confirm that structured sensor placement is critical for reproducible EMG-based posture and muscle imbalance studies. [12]

|METHODOLOGY

7.1 Method of Collection of Data:

•        SOURCE OF DATA - Individuals diagnosed with Upper Cross Syndrome in Belagavi City

•        STUDY DESIGN - Experimental study

•        STUDY TYPE – Clinical Trial

•        DURATION OF STUDY - 1 year

•        STUDY POPULATION - Subjects of all genders clinically diagnosed with Upper Cross Syndrome 18-25 years [6]

•        SAMPLING TYPE - Purposive Sampling

•        SAMPLE SIZE (n) - 36 (18 in each group)

MATERIALS USED:

1.Informed Consent Process

2.Data Collection Sheets

3.Pen/Paper/Marker Pen

4.Disposable gloves

TOOLS AND EQUIPMENTS:

1.Goniometer (r=0.85-0.98)

2.Treatment plinth

3.Surface EMG (r = 0.80–0.95) [11,12]

7.2. Inclusion Criteria:

1. Age 18 - 25 years.[6]
2. Forward head posture - craniovertebral angle > 50° [7]
3. At least two of the following :

•         Tight pectoralis minor/major on muscle length test

•         Tight upper trapezius on palpation and muscle length test

•         Weakness of lower trapezius/serratus anterior on clinical muscle tests.

Exclusion Criteria:

1. History of shoulder or spinal surgery in the past year.[3,4]
2. Partial or full-thickness rotator cuff tear, adhesive capsulitis, neurogenic radiculopathy, or other diagnosed shoulder pathology requiring surgery.[3,4]
3. Contraindications to spinal manipulation: known osteoporosis, vertebral fracture, spinal infection, malignancy, bleeding disorder or current anticoagulant therapy, uncontrolled systemic disease, signs of upper motor neuron lesion.[3,4]
4. Received spinal or shoulder manipulation within last 4 weeks.[3,4]

7**.3 OUTCOME MEASURES**:

1. Craniovertebral angle (ICC = 0.85-0.98) [7]

Using photogrammetry-Kinovea app

Lateral photograph-

1.     Participant  should be standing with neutral gaze and arms relaxed.

2.     Use markers on tragus of ear, C7 spinous process, and acromion to calculate craniovertebral angle (CVA = angle between horizontal through C7 and line C7-tragus).

Anterior photograph-

1.     Use landmarks on both acromion to quantify shoulder protraction/relative distances if needed.

2.     Take 2 photos and use the average

2. APLEY’S SCRATCH TEST (r=0.95) [9]

1.     Position: Patient may stand or sit comfortably.

2.     Ask the patient to reach one hand over the same-side shoulder and behind the neck to touch the superior angle of the opposite scapula, this tests abduction and external rotation.

3.     Ask the patient to reach the opposite hand behind the back and upward to try touching the inferior angle of the opposite scapula , this tests adduction and internal rotation.

4.     Compare both sides for range.

3. SURFACE EMG

Muscles to be Assessed –

A.    TIGHT – (TONIC)

•        Upper Trapezius

•        Pectoralis Major

B.    WEAK – (PHASIC)

•        Lower Trapezius

•        Serratus Anterior

Skin preparation:

1. Shave excess hair at the electrode site.

2. Clean the skin with alcohol to remove oil and dead cells.

3. Allow to dry completely to reduce skin impedance

4. Electrode type:

5. Use surface electrodes with an inter-electrode distance of about 2 cm (center-to-center).

6. Reference (ground) electrode:

7. Place on a bony, electrically neutral site, such as the clavicle, acromion, or olecranon process.

8. Ensures stable baseline and noise reduction.

9. Upper Trapezius [11,12]

10. Purpose: Represents an overactive muscle in UCS.

11. Location: Midway between the C7 spinous process and the acromion process.

12. Orientation: Electrodes placed parallel to the line between these two landmarks (fiber direction).

13. Reference electrode: Over the C7 spinous process or on the acromion.

14. Avoid placing too close to the neck or shoulder joint to prevent cross-talk.

15. Patient position: Sitting or standing upright with relaxed shoulders.

B. Pectoralis Major [11,12]

1. Purpose: To evaluate reduction in overactivity or compensatory dominance after intervention.
2. Placement:

•        Clavicular head: 2 cm below the clavicle, oriented toward the anterior axillary line.

•        Sternal head (optional): Oblique placement midway between sternum and anterior axillary fold.

•        Reference electrode: Over the sternum or acromion.

iii.          Testing position: Supine or standing with resisted horizontal adduction (at 60° shoulder flexion).

C. Lower Trapezius [11,12]

1. Purpose: Typically an inhibited muscle in UCS; vital for scapular depression and upward rotation.
2. Location: Two-thirds of the distance from spine of scapula to T8 spinous process (following inferomedial fibers).
3. Orientation: Oblique, parallel to fiber direction.
4. Reference electrode: Over T12 or acromion.
5. Testing position: Prone or standing in scapular retraction and depression (135° shoulder abduction).

D. Serratus Anterior [11,12]

1. Purpose: A scapular stabilizer often inhibited in UCS; crucial for upward rotation and protraction.
2. Location: Mid-axillary line at the 6th–8th ribs (between latissimus dorsi and pectoralis major borders).
3. Orientation: Vertical or slightly oblique along rib direction.
4. Reference electrode: Over C7 or acromion.
5. Testing position: Seated or standing with shoulder flexed to 90° performing scapular protraction
6. PROCEDURE:

1.     An Ethical Clearance will be obtained from the Institutional Ethical Committee.

2.     The study will be registered under the Clinical Trials Registry- India(CTRI). The intervention will begin once the CTRI registration number is obtained.

3.     Participants will be screened based on the Inclusion and Exclusion Criteria

4.     The purpose of the study will be explained and written Informed Consent will be obtained from all the subjects.

5.     A brief demographic data will be obtained from the participants prior to the assessment.

6.     The participants will be randomly allotted into 2 groups, Group A & Group B.

•        Group A will receive Thoracic Manipulation + Janda-based exercises

•        Group B will receive Janda-based exercises.

7.     The outcome measures will be assessed pre and post treatment.

INTERVENTION

Group A (Experimental): Thoracic Manipulation + Janda-based Exercises [10]

1.     Participants in the manipulation group received a prone high-velocity, low-amplitude thrust manipulation technique directed bilaterally to the upper thoracic (C7-T3) and mid-thoracic (T4- T9) spine.

2.     If there was no audible cavitation heard , a second attempt will be  performed.

3.     An audible cavitation would be expected for each manipulation to be considered a success.

4.     Audible cavitations will be recorded for each group.

Janda-based Exercises [10]

1. Stretching of tonic muscles (pectoralis, upper trapezius).
2. Activation of phasic muscles using low-load, precise control exercises (chin tucks, prone Y/T/W, serratus punches).
3. Integration into postural and functional patterns (wall slides, scapular setting).

Group B (Control): Janda-based Exercises [10]

1.     Stretching of tonic muscles (pectoralis, upper trapezius)

2.     Activation of phasic muscles using low-load, precise control exercises (chin tucks, prone Y/T/W, serratus punches).

3.     Integration into postural and functional patterns (wall slides, scapular setting).

4.     3 sessions per week for a period of 4 weeks.

Both groups will receive intervention for 30-45 minutes.

SAMPLE SIZE ESTIMATION

Sample size determination

To determine sample size, technique of estimating sample size for Paired “t” test was used:

             Where,

Significance level (5%)

Effect size (0.75)

Power (80%)

Anticipated drop outs (10%)

Thus, the sample size for this study is determined as 16 + 2 = 18 (Each group).