Related Experiment Video
Updated: Mar 13, 2026
Providing Visual Biofeedback Using Brightness Mode Ultrasound During a Golf Swing
Published on: August 25, 2022
Trunk Muscle Function Deficit in Youth Baseball Pitchers With Excessive Contralateral Trunk Tilt During Pitching
Sakiko Oyama1, Andrew G Waldhelm, Araceli R Sosa
1*Department of Health and Kinesiology, University of Texas at San Antonio, San Antonio, Texas; †University of Incarnate Word; ‡University of Texas at San Antonio, San Antonio, Texas; and §Department of Physical Therapy, University of South Alabama, Mobile, AL.
Objective:
Pitching technique is one of many factors that affect injury risk. Exhibiting excessive contralateral trunk tilt (CLT) during pitching has been linked to higher ball speed but also to increased joint loading. Deficit in trunk muscle strength has been suggested as an underlying cause of this movement pattern. The purpose of the study was to compare trunk muscle strength between youth baseball pitchers with varying degree of CLT during pitching.
Design:
Cross-sectional study.
Setting:
Baseball practice fields.
Participants:
Twenty-eight youth baseball pitchers.
Independent Variables:
Pitching technique was captured using a video camera. Based on the 2-dimensional trunk contralateral flexion angle, pitchers were categorized into low (<15 degrees), moderate (15-30 degrees), or high (>30 degrees) CLT groups.
Main Outcome Measures:
Maximum isometric strength tests for trunk flexion, extension, and bilateral rotation, measured using a dynamometer.
Results:
The pitchers with high CLT (n = 10) had longer pitching experience (P = 0.014), produced higher ball speed (P = 0.003) compared with the pitchers with moderate (n = 10) and low (n = 8) CLT, but demonstrated greater asymmetry in trunk rotation strength (relative weakness in rotation strength toward dominant side) compared with the pitchers with low CLT (P = 0.015).
Conclusions:
Excessive CLT may be a strategy that young pitchers learn to achieve higher ball velocity but also may be associated with imbalance between the oblique muscles on dominant and nondominant side, which may be acquired from repetitive pitching. Strengthening and emphasizing the use of dominant side oblique muscles may keep pitchers from leaning excessively during pitching and thus decrease joint loading.
Related Concept Videos
01:19Muscles that Move the Head
The bilateral sternocleidomastoid, or SCM, and the suprahyoid and infrahyoid muscles are significant head flexors. The SCM muscles originate at the sternum and clavicle and attach to the mastoid process of the temporal bone. The SCM contracts bilaterally to bend the head forward, whereas...
01:18Axial and Appendicular Muscles
Axial Muscles
Axial muscles, situated along the body's midline, are intricately connected to the axial skeleton, which includes the skull, spine, ribs, and sternum. These muscles facilitate facial expressions and...
01:31Muscles that Move the Arm
The pectoralis major has two origins. Its clavicular head originates on the medial half of the clavicle. In contrast, the sternocostal head originates on the costal cartilages of ribs 1-6, the sternum, and the aponeurosis of the external oblique of the...
01:16Muscles that Move the Forearm
Forearm Flexors
The biceps brachii, brachialis, and brachioradialis are forearm flexors. The biceps brachii is made up of two heads. Its long head originates at the supraglenoid tubercle of the scapula, whereas that of the short head is...
01:24Muscle Coordination and Action
Agonists
Agonist muscles, often called prime movers, are the primary muscles responsible for producing a specific movement....
01:23Muscles of the Shoulder
Anterior Thoracic Muscles
The anterior thoracic muscles include the serratus anterior, subclavius, and...