Healthy Male and Female Subjects
Conditions
Keywords
mobilization, proprioception, strength, shoulder
Brief summary
This randomized, double-blind study examines the acute effects of shoulder mobilization on muscle strength and proprioception in healthy individuals. Forty-eight participants (aged 18-25) were randomly assigned to either a mobilization or sham intervention group. Muscle strength and proprioception were assessed before and after treatment. The mobilization group received passive shoulder joint glides, while the sham group underwent a placebo procedure. The study aims to determine whether mobilization affects strength and proprioception immediately.
Detailed description
Summary of the Study This randomized, double-blind study investigates the acute effects of shoulder joint mobilization on muscle strength and proprioception in healthy individuals compared to a sham intervention. Background: The shoulder joint is highly mobile and prone to injury, with rehabilitation often including manual therapy techniques like joint mobilization. Mobilization may enhance joint stability, neuromuscular control, and proprioception by stimulating mechanoreceptors. However, its immediate effects on shoulder proprioception and strength remain unclear. Methods: Participants: 48 healthy university students (aged 18-25) randomly assigned to either the mobilization or sham group. Assessments: Muscle strength (using a handheld dynamometer) and proprioception (laser pointer-assisted joint position reproduction test) were measured before and after the intervention. Intervention: The mobilization group received passive shoulder joint glides, while the sham group underwent a placebo procedure without actual joint movement. Conclusion: This study aims to determine whether shoulder mobilization has immediate effects on proprioception and strength.
Interventions
OTHERJoint mobilization
Participants receive passive shoulder joint mobilization on the dominant-side glenohumeral joint. The mobilization includes inferior, anterior, and posterior glide techniques, each performed for 1 minute at a frequency of 0.5 Hz, with a 30-second rest between each mobilization. The participant is positioned comfortably to support the joint's range of motion.
OTHERSham
In the sham intervention, the practitioner mimics the technique of shoulder mobilization but does not apply any actual movement or glide effect on the joint. The procedure is designed to closely resemble the real intervention in terms of duration, rhythm, and the practitioner's handling of the participant's shoulder. The practitioner will use superficial touch on the glenohumeral joint without applying any of the mobilizing forces necessary to move the joint.
Sponsors
Acibadem University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
DOUBLE (Subject, Outcomes Assessor)
Intervention model description
Participants are randomly assigned to either the shoulder mobilization group or the sham mobilization group, and they remain in their assigned group throughout the study. This design allows for a direct comparison of the acute effects of mobilization on muscle strength and proprioception.
Eligibility
Sex/Gender
ALL
Age
18 Years to 25 Years
Healthy volunteers
Yes
Inclusion criteria
* Healthy university students aged 18-25 years.
Exclusion criteria
* Individuals with orthopedic problems in the shoulder complex. * Those who have undergone previous shoulder surgery. * Participants with prior knowledge of joint mobilization techniques that could affect the sham intervention.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Proprioception | Before the intervention | Laser pointer-assisted joint position reproduction test for shoulder: A laser pointer is strapped 5 cm above the lateral epicondyle. Participants actively move their arm to a predefined position (90° flexion or abduction), and the laser projection is marked. After lowering their arm and closing their eyes, they attempt to replicate the same position. The difference between the initial and reproduced positions (in millimeters) is measured |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Muscle Strength | Before the intervention | Hand-held dynamometer (Lafayette) Muscle strength will be measured using a hand-held dynamometer (Lafayette). The assessment will focus on the shoulder flexors, abductors, internal rotators, and external rotators. Three measurements for each muscle group will be taken, and the average value will be recorded in kilograms (kg). |
Countries
Turkey (Türkiye)
Participant flow
Recruitment details
Participants were recruited from a university setting between April and May 2025. All participants provided written informed consent.
Pre-assignment details
48 participants were assessed for eligibility and randomized before any intervention was delivered. No dropouts or exclusions occurred.
Participants by arm
| Arm | Count |
|---|---|
| Mobilization Group Received passive glenohumeral joint mobilization (inferior, anterior, posterior glides). | 24 |
| Sham Group Received simulated mobilization without mechanical input. | 24 |
| Total | 48 |
Baseline characteristics
| Characteristic | Mobilization Group | Sham Group | Total |
|---|---|---|---|
| Age, Continuous | 21.08 years | 20.91 years | 21 years |
| Ethnicity (NIH/OMB) Hispanic or Latino | 0 Participants | 0 Participants | 0 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 0 Participants | 0 Participants | 0 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 24 Participants | 24 Participants | 48 Participants |
| Muscle strength Abduction | 17.6 kg | 17.8 kg | 17.6 kg |
| Muscle strength External Rotation | 9.82 kg | 9.4 kg | 9.47 kg |
| Muscle strength Flexion | 17.3 kg | 19.5 kg | 17.6 kg |
| Muscle strength Internal Rotation | 15.4 kg | 14.6 kg | 14.6 kg |
| Proprioception Error Abduction | 86.7 mm | 85.3 mm | 86.2 mm |
| Proprioception Error Flexion | 54 mm | 62.8 mm | 57.3 mm |
| Sex: Female, Male Female | 14 Participants | 13 Participants | 27 Participants |
| Sex: Female, Male Male | 10 Participants | 11 Participants | 21 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 24 | 0 / 24 |
| other Total, other adverse events | 0 / 24 | 0 / 24 |
| serious Total, serious adverse events | 0 / 24 | 0 / 24 |
Outcome results
Primary
Proprioception
Laser pointer-assisted joint position reproduction test for shoulder: A laser pointer is strapped 5 cm above the lateral epicondyle. Participants actively move their arm to a predefined position (90° flexion or abduction), and the laser projection is marked. After lowering their arm and closing their eyes, they attempt to replicate the same position. The difference between the initial and reproduced positions (in millimeters) is measured
Time frame: Before the intervention
| Arm | Measure | Group | Value (MEDIAN) | Dispersion |
|---|---|---|---|---|
| Mobilization Group | Proprioception | Proprioception Flexion | 54 mm | Standard Deviation 20.9 |
| Mobilization Group | Proprioception | Proprioception Abduction | 86.7 mm | Standard Deviation 32.1 |
| Sham Group | Proprioception | Proprioception Flexion | 62.8 mm | Standard Deviation 22.8 |
| Sham Group | Proprioception | Proprioception Abduction | 85.3 mm | Standard Deviation 26.6 |
Primary
Proprioception
Laser pointer-assisted joint position reproduction test for shoulder: A laser pointer is strapped 5 cm above the lateral epicondyle. Participants actively move their arm to a predefined position (90° flexion or abduction), and the laser projection is marked. After lowering their arm and closing their eyes, they attempt to replicate the same position. The difference between the initial and reproduced positions (in millimeters) is measured
Time frame: Immediately after intervention
| Arm | Measure | Group | Value (MEDIAN) | Dispersion |
|---|---|---|---|---|
| Mobilization Group | Proprioception | Proprioception Flexion | 52.3 mm | Standard Deviation 23.9 |
| Mobilization Group | Proprioception | Proprioception Abduction | 91.2 mm | Standard Deviation 29 |
| Sham Group | Proprioception | Proprioception Flexion | 52.2 mm | Standard Deviation 78.3 |
| Sham Group | Proprioception | Proprioception Abduction | 78.3 mm | Standard Deviation 32.5 |
Secondary
Muscle Strength
Hand-held dynamometer (Lafayette) Muscle strength will be measured using a hand-held dynamometer (Lafayette). The assessment will focus on the shoulder flexors, abductors, internal rotators, and external rotators. Three measurements for each muscle group will be taken, and the average value will be recorded in kilograms (kg).
Time frame: Before the intervention
| Arm | Measure | Group | Value (MEDIAN) | Dispersion |
|---|---|---|---|---|
| Mobilization Group | Muscle Strength | Shoulder Flexion | 17.3 kg | Standard Deviation 7.59 |
| Mobilization Group | Muscle Strength | Shoulder Abduction | 17.6 kg | Standard Deviation 7.32 |
| Mobilization Group | Muscle Strength | Shoulder External Rotation | 9.82 kg | Standard Deviation 3.6 |
| Mobilization Group | Muscle Strength | Shoulder Internal Rotation | 15.4 kg | Standard Deviation 5.84 |
| Sham Group | Muscle Strength | Shoulder Internal Rotation | 14.6 kg | Standard Deviation 5.91 |
| Sham Group | Muscle Strength | Shoulder Flexion | 19.5 kg | Standard Deviation 9.08 |
| Sham Group | Muscle Strength | Shoulder External Rotation | 9.40 kg | Standard Deviation 4.1 |
| Sham Group | Muscle Strength | Shoulder Abduction | 17.8 kg | Standard Deviation 7.58 |
Secondary
Muscle Strength
Hand-held dynamometer (Lafayette) Muscle strength will be measured using a hand-held dynamometer (Lafayette). The assessment will focus on the shoulder flexors, abductors, internal rotators, and external rotators. Three measurements for each muscle group will be taken, and the average value will be recorded in kilograms (kg).
Time frame: Immediately after intervention
| Arm | Measure | Group | Value (MEDIAN) | Dispersion |
|---|---|---|---|---|
| Mobilization Group | Muscle Strength | Shoulder Flexion | 18.3 kg | Standard Deviation 8.03 |
| Mobilization Group | Muscle Strength | Shoulder Abduction | 16.6 kg | Standard Deviation 6.81 |
| Mobilization Group | Muscle Strength | Shoulder External Rotation | 9.83 kg | Standard Deviation 3.05 |
| Mobilization Group | Muscle Strength | Shoulder Internal Rotation | 15.1 kg | Standard Deviation 5.86 |
| Sham Group | Muscle Strength | Shoulder Internal Rotation | 14.2 kg | Standard Deviation 6.45 |
| Sham Group | Muscle Strength | Shoulder Flexion | 18.5 kg | Standard Deviation 9.42 |
| Sham Group | Muscle Strength | Shoulder External Rotation | 9.95 kg | Standard Deviation 4.87 |
| Sham Group | Muscle Strength | Shoulder Abduction | 16.5 kg | Standard Deviation 8.35 |