Ultrasonographic and Myotonometric Evaluation of the Shoulder Girdle After an Isokinetic Muscle Fatigue Protocol

Abstract

Objectives: The aim of the study was to investigate supraspinatus tendon thickness, acromiohumeral distance (AHD), and stiffness/creep measures of the shoulder girdle in overhead asymptomatic athletes in muscle fatigue conditions. Design: Observational, case series study. Setting: Biomechanics and motion analysis lab. Participants: Twenty-four male overhead volleyball (n = 8), handball (n = 8), and tennis (n = 8) athletes. All subjects were without shoulder injury history. Main Outcome Measure: The subjects were tested for supraspinatus tendon thickness (in short and long axis), AHD using ultrasound scans and stiffness/creep of upper trapezius, infraspinatus, anterior and posterior deltoid, and pectoralis major using the myotonometer device before and immediately after a fatigue protocol. Intervention: The fatigue protocol consisted of 3 sets of 32 maximum isokinetic concentric contractions performing shoulder internal and external rotation at isokinetic speed of 120°/s. Results: A significant increase in supraspinatus tendon thickness (both in short and long axis) (P = .045 and P = .01, respectively) and a reduction in AHD (P = .01) were found after an isokinetic protocol. The stiffness increased significantly in upper trapezius (P ≤ .01), infraspinatus (P = .003), posterior deltoid (P = .047), and pectoralis major (P = .01), whereas the creep showed a significant decrement for upper trapezius (P = .001) and infraspinatus (P = .003). Conclusion: The present study has demonstrated the postexercise fatigue in overhead athletes. The increase of stiffness (reduction of muscle creep) and tendon thickness (simultaneous to the reduction of AHD) may indicate rotator cuff overloading as a primary intrinsic tendon pathology process.

Quadriceps and Patellar Tendon Thickness and Stiffness in Elite Track Cyclists: An Ultrasonographic and Myotonometric Evaluation

“…Muscle stiffness is defined as the property that characterizes resistance to the contraction of the external stretching force that deforms the initial shape of the tissue. Stiffness (N/m) was computed as S = a max .m probe / l, where a is the acceleration of the damped oscillation; m probe is the mass of the measurement mechanism and l is the probe displacement (Klich et al, 2019). The examiner located the probe perpendicular to the tested area.…”

“…Thus, the assessment of thigh muscles and tendons using ultrasonography and myotonometry could be used to assess the effects of muscle loading during cycling competitions. Diagnostic ultrasound imaging and myotonometry have been proposed as reliable research and clinical instruments to evaluate morphological and mechanical properties of skeletal muscles (Bizzini and Mannion, 2003;Klich et al, 2019). Diagnostic ultrasound imaging has been previously used to assess the reliability and magnitude of QT and PT characteristics in volleyball players (Kulig et al, 2013;Visnes et al, 2015).…”

Fatigue-Induced Scapular Dyskinesis in Healthy Overhead Athletes

“…This observational case-series study involved two repeated kinematic measurements taken before and following the fatigue protocol, as detailed in Klich et al (2019). Each measurement included three upper limb movements on the right side (dominant for all subjects): (i) elevation, (ii) abduction in the scapular plane, (iii) intra-extra rotation (with the elbow flexed at 90 degrees).…”

“…Between the repetitions of the kinematic tests, participants performed a fatigue protocol on an isokinetic dynamometer (Biodex Multi-Joint System 4 Pro, Biodex Medical Systems, Inc., Shirley, NY, United States). The device was set for upper limb intra-extra rotation from 0 degrees (internal rotation) to 90 degrees (external rotation), while the elbow was flexed at 90 degrees and the shoulder abducted at 90 degrees (Klich et al, 2019). Participants seated at the isokinetic dynamometer with their back against a chair and were secured with belts in order to avoid trunk or shoulder movements.…”

“…In this study, we investigated the changes in the humeral and scapular rotation following an objective fatigue protocol (isokinetic exercise) on the intra and extra rotator muscles (Klich et al, 2019). Weakness in such muscle groups were previously associated to variations in scapula-humeral rotations (dyskinesis) and to the migration of the humeral head toward the acromion (Maenhout et al, 2015;Chopp-Hurley et al, 2016).…”