Are pectoralis minor length and posterior shoulder tightness associated with patient-reported shoulder pain and disability?

Background: Pectoralis minor (PM) shortening and posterior shoulder tightness (PST) are considered potential soft tissue alterations associated with rotator cuff related shoulder pain (RCRSP). Yet, their precise contribution to pain and disability remains unclear.

Purpose: To explore the association between both PM length and PST and self-reported shoulder pain and disability in individuals with and without RCRSP.

Comparison of specific and non-specific treatment approaches for individuals with posterior capsule tightness and shoulder impingement symptoms: A randomized controlled trial.

Background: Posterior capsule tightness (PCT) is associated with shoulder pain and altered shoulder kinematics, range of motion (ROM), external rotation (ER) strength, and pain sensitization.

Objective: To assess the effects of two interventions on shoulder kinematics, Shoulder Pain and Disability Index (SPADI) scores, ROM, strength, and pressure pain threshold (PPT) in individuals with PCT and shoulder impingement symptoms.

Methods: In this prospectively registered randomized controlled trial 59 individuals were randomized to either an Experimental Intervention Group (EIG, n=31) or a Control Intervention Group (CIG, n=28).

Effect of Posterior Capsule Tightness and Humeral Retroversion on 5 Glenohumeral Joint Range of Motion Measurements: A Cadaveric Study.

Background: Altered glenohumeral joint range of motion can be caused by increased humeral retroversion (HR) and/or posterior capsule tightness (PCT). To make informed clinical decisions, it is vital to understand how HR and PCT alterations, individually and in combination, affect joint range of motion measurements.

Purpose: To evaluate the effect of experimental tissue alterations on clinical range of motion measures.

The Influence of Glenohumeral Joint Posterior Capsule Tightness and Impingement Symptoms on Shoulder Impairments and Kinematics.

Background: Posterior capsule tightness (PCT) and shoulder impingement syndrome (SIS) symptoms are both associated with altered shoulder biomechanics and impairments. However, their combined effect on kinematics, pain, range of motion (ROM), strength, and function remain unknown.

Objective: The purpose of this study was to determine if the combination of PCT and SIS affects scapular and humeral kinematics, glenohumeral joint ROM, glenohumeral joint external rotation strength, pain, and function differently than does either factor (PCT or SIS) alone.

The influence of posterior glenohumeral joint capsule tightness and humeral retroversion on clinical measurements.

Objectives: To assess the influence of posterior capsule tightness and humeral retroversion on shoulder motion measurements.

Design: Cross-Sectional study.

Setting: Controlled university laboratory.

Shoulder external rotation range of motion and pectoralis minor length in individuals with and without shoulder pain.

: There is evidence that pectoralis minor (PM) length influences scapula position and that scapula position relates to glenohumeral joint (GHJ) external rotation (ER) range of motion (ROM). : To explore the association between PM resting length and GHJ ER ROM in individuals with and without shoulder pain. The influence of GHJ ER ROM measurement position on this association was also evaluated.

Posterior Shoulder Tightness: To Treat or Not to Treat?

Shoulder pain is a common musculoskeletal complaint that is difficult to treat because of the biomechanical complexity of the shoulder region, the interplay between mobility and stability, and the vital role played by the shoulder in moving, positioning, and providing stability for hand function. Despite advances in biomechanics and pain science, there is still much to learn about how impairments influence shoulder function and health. One impairment, posterior shoulder tightness (PST), is often noted in individuals with shoulder pain and consequently has generated much discussion and debate in recent years.

Effects of a stretching protocol for the pectoralis minor on muscle length, function, and scapular kinematics in individuals with and without shoulder pain.

Study Design: Parallel-group intervention with repeated measures.

Introduction: Shortening of the pectoralis minor (PM) may contribute to alterations in scapular kinematics.

Purpose Of The Study: To evaluate the effects of a stretching protocol on function, muscle length, and scapular kinematics in subjects with and without shoulder pain.

Reliability of measuring pectoralis minor muscle resting length in subjects with and without signs of shoulder impingement.

Background: Pectoralis minor adaptive shortening may change scapula resting position and scapular kinematics during arm elevation. A reliable and clinically feasible method for measuring pectoralis minor length will be useful for clinical decision making when evaluating and treating individuals with shoulder pain and dysfunction.

Objectives: To evaluate intrarater, interrater, and between-day reliability of a pectoralis minor (PM) muscle length measurement in subjects with and without signs of shoulder impingement.

Stride Leg Ground Reaction Forces Predict Throwing Velocity in Adult Recreational Baseball Pitchers.

Ground reaction forces produced during baseball pitching have a significant impact in the development of ball velocity. However, the measurement of only one leg and small sample sizes in these studies curb the understanding of ground reaction forces as they relate to pitching. This study aimed to further clarify the role ground reaction forces play in developing pitching velocity.

Validity and reliability of the Low Flexion measurement for posterior glenohumeral joint capsule tightness.

Posterior shoulder tightness is a problem in many patients with shoulder pain. Tightness manifests as decreased range of motion (ROM) caused by loss of posterior capsule or posterior shoulder muscle flexibility. The posterior capsule often loses flexibility in throwing athletes and may also be present in patients with impingement symptoms.

Gender differences between muscle activation and onset timing of the four subdivisions of trapezius during humerothoracic elevation.

The aim of this study was to provide a description of gender differences of the normal muscle activation patterns of the four subdivisions of the trapezius (clavicular, descending, transverse, ascending) during arm elevation. Surface EMG was collected from these four subdivisions from twenty-two healthy subjects (12 females, 10 males) during arm elevation in the scapular plane. Percent activation (RMS) of each subdivision was compared between genders across arm angles and elevation phase and onset time of each subdivision was compared between genders.

Scapula kinematics differ by body mass index.

The biomechanical changes due to increased arm mass in individuals with high body mass index (BMI) may lead to altered scapular motions at the shoulder joint. Scapula kinematic alterations are often associated with shoulder pain and pathology, and if present in overweight or obese individuals could impact shoulder health. The purpose of this study was to examine if scapula biomechanics differ between groups separated by BMI.

Validity of measuring humeral torsion using palpation of bicipital tuberosities.

The magnitude of humeral torsion (HT) affects the internal and external rotation range of motion at the shoulder. Currently imaging is required to quantify the HT angle, however, factors such as cost and non-availability of imaging to musculoskeletal clinicians limits its use. The aim of this study was to examine the validity of palpation of the bicipital tuberosities as an alternative to imaging for quantifying HT angles.

Three-dimensional scapula kinematics and shoulder function examined before and after surgical treatment for breast cancer.

Shoulder motion loss following surgical treatment of breast cancer is common and may be associated with surgery-related soft tissue changes and altered shoulder kinematics. Knowledge of short term biomechanical changes at the shoulder will inform treatment decisions and may help prevent the development of shoulder pathology. Shoulder motion loss following surgery also impacts quality of life and shoulder function, and measuring function with a shoulder-specific tool may direct rehabilitation.

Quantifying strain on posterior shoulder tissues during 5 simulated clinical tests: a cadaver study.

Study Design: Controlled laboratory study using a repeated-measures approach.

Objective: To quantify the amount of strain on cadaver posterior shoulder tissues during simulated clinical tests across different tissue conditions.

Background: Several clinical tests are used to quantify posterior glenohumeral joint (GHJ) tissue tightness; however, the ability of these tests to directly assess the flexibility or tightness of the posterior capsule has not been evaluated.

Reproducibility of a measurement for latissimus dorsi muscle length.

ABSTRACT Latissimus dorsi is a muscle theorized to undergo length changes due to shoulder region pathology or treatment such as stretching. A latissimus dorsi length measurement would be valuable to determine if length changes have occurred within an individual over time. With no such measurement known, we examined a proposed technique believed to isolate latissimus dorsi.

Scapula kinematic alterations following a modified push-up plus task.

Scapular kinematic and muscle activity alterations have been identified in individuals with subacromial impingement syndrome of the shoulder, including workers and athletes who regularly perform overhead activities. Serratus anterior fatigue is a proposed mechanism for these kinematic alterations, although no direct evidence supports such a relationship. The purpose of this study was to examine three-dimensional scapula kinematics in asymptomatic participants before and after a task intended to preferentially fatigue serratus anterior.

Scapular muscle activation and co-activation following a fatigue task.

Scapular muscles precisely move the scapulothoracic articulation and if fatigued may contribute to pathology. Fatigue of serratus anterior may be a mechanism for shoulder pathology by altering scapula motions and requiring compensation by other shoulder muscles. A total of 28 asymptomatic subjects performed a task to fatigue the serratus anterior, while muscle activity was recorded from three muscles.

A longitudinal analysis of the effects of a preventive exercise programme on the factors that predict shoulder pain in construction apprentices.

Construction apprentices are at risk for developing shoulder pain with increasing exposure to repetitive overhead work. Risk may decrease if shoulder biomechanics are optimised and if risk factors that contribute to shoulder pain onset are identified. This prospective cohort study examined demographic and work-related factors and shoulder pain onset over 2 years in a cohort of 240 construction apprentices.

Measurement of pectoralis minor muscle length: validation and clinical application.

Study Design: Clinical measurement validity study.

Objectives: To validate the measurement of the pectoralis minor muscle length using palpable landmarks and to explore the accuracy of the measurement using a clinical instrument.

Background: The pectoralis minor is believed to adaptively shorten.

Clinical measurement of posterior shoulder flexibility.

The objectives of this study were to determine both the intra-rater reliability and the smallest real difference necessary to detect meaningful clinical changes over an 8-12 week period for three clinical measures of posterior shoulder flexibility. Posterior shoulder tightness has been associated with abnormal humeral head translations that narrow the subacromial space and contribute to impingement. Posterior shoulder stretching to normalize joint kinematics is often used when treating individuals with subacromial impingement.

Comparison of three stretches for the pectoralis minor muscle.

Pectoralis minor adaptive shortening in healthy individuals is associated with altered scapular kinematics similar to the alterations demonstrated in individuals with subacromial impingement. This associative relationship suggests that stretching of the pectoralis minor may improve scapular kinematics and assist in the management of shoulder impingement. Several stretches for the pectoralis minor are used clinically, although it is not known which stretch optimally lengthens the muscle.

Resting position variables at the shoulder: evidence to support a posture-impairment association.

Background And Purpose: A relationship between posture and impairment at the shoulder is theorized, but not supported by evidence. It is proposed that posture and impairment are not directly related, but linked by movement dysfunction. The purpose of this analysis was to explore the relationships among posture, pectoralis minor muscle length, and movement alterations at the shoulder.