The effect of shoulder position on inferior glenohumeral mobilization

Is the cadaveric model valid for examining orthopaedic manual therapy techniques? A cross-sectional comparative study in vivo and in vitro

BACKGROUND

Cadaveric models are sometimes used to test the effect of manual techniques. We have not found any studies comparing the effect of tibiotarsal joint distraction on cadaveric models versus live models for clinical use. The aim was to compare the effect on tibiotarsal joint distraction movement when applying three force magnitudes of tibiotarsal axial traction technique force between a cadaveric model and volunteers. In addition, to compare the magnitude of force applied between the cadaveric model and volunteers. Finally, to assess the reliability of applying the same magnitude of force in three magnitudes of tibiotarsal axial traction force.

METHODS

A cross-sectional comparative study was conducted. Sixty ankle joints were in open-packed position and three magnitudes of tibiotarsal axial traction technique force were applied. Tibiotarsal joint distraction movement was measured with ultrasound.

FINDINGS

No differences were found in applied force or tibiotarsal joint distraction between volunteers and cadavers in each magnitude of force (p > 0.05). The application of the technique showed moderate reliability for detecting low forces in both models. For medium and high force, it showed good reliability in the in vitro model and excellent reliability in the live model.

INTERPRETATION

The amount of distraction produced in the tibiotarsal joint was similar in volunteers and cadavers. The cadaveric model is a valid model for testing and investigating orthopaedic manual therapy techniques. The force applied was similar in the two models. Medium and high force detection showed good reliability, while low force showed moderate.

Effect of Scapular Fixation on Lateral Movement and Scapular Rotation during Glenohumeral Lateral Distraction Mobilisation

BACKGROUND

Glenohumeral lateral distraction mobilisation (GLDM) is used in patients with shoulder mobility dysfunction. No one has examined the effect of scapular fixation during GLDM. The aim was to measure and compare the lateral movement of the humeral head and the rotational movement of the scapula when three different magnitudes of forces were applied during GLDM, with and without scapular fixation.

METHODS

Seventeen volunteers were recruited (n = 25 shoulders). Three magnitudes of GLDM force (low, medium, and high) were applied under fixation and non-fixation scapular conditions in the open-packed position. Lateral movement of the humeral head was assessed with ultrasound, and a universal goniometer assessed scapular rotation.

RESULTS

The most significant increase in the distance between the coracoid and the humeral head occurred in the scapular fixation condition at all three high-force magnitudes (3.72 mm; p < 0.001). More significant scapular rotation was observed in the non-scapular fixation condition (12.71°). A difference in scapula rotation (10.1°) was observed between scapular fixation and non-scapular fixation during high-force application.

CONCLUSIONS

Scapular fixation resulted in more significant lateral movement of the humeral head than in the non-scapular fixation condition during three intensities of GLDM forces. The scapular position did not change during GLDM with the scapular fixation condition.

The Effect of Scapular Fixation on Scapular and Humeral Head Movements during Glenohumeral Axial Distraction Mobilization

Background and Objectives: Glenohumeral axial distraction mobilization (GADM) is a usual mobilization technique for patients with shoulder dysfunctions. The effect of scapular fixation on the movement of the scapula and the humeral head during GADM is unknown. To analyze the caudal movement of the humeral head and the rotatory movement of the scapula when applying three different intensities of GADM force with or without scapular fixation. Materials and Methods: Fifteen healthy subjects (mean age 28 ± 9 years; 73.3% male) participated in the study (twenty-eight upper limbs). Low-, medium- and high-force GADM in open-packed position were applied in scapular fixation and non-fixation conditions. The caudal movement of humeral head was evaluated by ultrasound measurements. The scapular rotatory movement was assessed with a universal goniometer. The magnitude of force applied during GADM and the region (glenohumeral joint, shoulder girdle, neck or nowhere) where subjects felt the effect of GADM mobilization were also recorded. Results: A greater caudal movement of the humeral head was observed in the non-scapular fixation condition at the three grades of GADM (p < 0.008). The rotatory movement of the scapula in the scapular fixation condition was practically insignificant (0.05−0.75°). The high-force GADM rotated scapula 18.6° in non-scapular fixation condition. Subjects reported a greater feeling of effect of the techniques in the glenohumeral joint with scapular fixation compared with non-scapular fixation. Conclusions: The caudal movement of the humeral head and the scapular movement were significantly greater in non-scapular fixation condition than in scapular fixation condition for the three magnitudes of GADM force.

Ultrasound measurement of the effects of high, medium and low hip long-axis distraction mobilization forces on the joint space width and its correlation with the joint strain

BACKGROUND

No study has evaluated the mechanical effect of different magnitudes of long axis-distraction mobilization (LADM) force on hip joint space width (JSW) or the association between the separation of joint surfaces and the strain on hip capsular ligaments.

OBJECTIVE

To compare the joint separation when applying three different magnitudes of LADM forces (low, medium and high) and to analyse the correlation between joint separation, strain on the inferior ilio-femoral ligament and magnitude of applied force.

DESIGN

Repeated measures controlled laboratory cadaveric study.

METHODS

Three magnitudes of force were applied to 11 cadaveric hip joints (mean age 73 years). Ultrasound images were used to measure joint separation, and strain gauges recorded inferior ilio-femoral ligament strain during each condition.

RESULTS

The magnitude of joint separation was significantly different between low (0.23 ± 0.19 mm), medium (0.72 ± 0.22 mm) and high (2.62 ± 0.43 mm) forces (p < 0.001). There were significant associations between magnitude of force, joint separation and the strain on the inferior ilio-femoral ligament during LADM (r > 0.723; p < 0.001).

CONCLUSION

Hip joint separation and ligament strain during LADM are associated with the magnitude of the applied force.