Infraspinatus Research Articles

Pain referral area is reduced by remote pain.

Endogenous pain inhibitory mechanisms are known to reduce pain intensity, but whether they influence the size and distribution of pain referral is unclear. This study aimed to determine if referred pain is reduced by applying a remote, conditioning painful stimulus. Twenty-four healthy men participated in this randomized, crossover study with a control and conditioning session. Referred pain was induced from the infraspinatus muscle (dominant side) by a painful pressure for 60s. When applying pressure, the intensity was adjusted to a local pain intensity of 7/10 on a numerical rating scale. In the conditioning session, tonic painful pressure was simultaneously applied to the non-dominant leg during induction of referred pain. The area of referred pain was drawn onto a digital body chart and size extracted for data analysis. For the total group and in a subgroup with distinct patterns of referred pain (n=15/24), the pain area perceived in the back and front+back was smaller during the conditioning compared with the control (p<0.05). No significant difference was found between sessions in a subgroup only demonstrating local pain (n=9/24). Engaging the descending noxious inhibitory control reduced the size of pain areas predominately when distinct pain referral was present. Assuming a conditioning effect of descending inhibitory control acting on dorsal horn neurons, these findings may indicate that mechanisms underlying pain referral can be modulated by endogenous control. The findings may indicate that referred pain may be a useful proxy to evaluate sensitivity of central pain mechanisms as previously suggested. The current results indicate a link between endogenous inhibition and pain referral. Descending inhibitory control effects on pain referral support a spinal mechanism involved in pain referral. Future studies should investigate whether the spatial characteristics of referred pain (e.g. size, frequency of affected body regions and distribution away from the primary nociceptive stimulus) can useful to evaluate the efficiency of endogenous pain modulation.

CORR Insights®: Imbalance in Axial-plane Rotator Cuff Fatty Infiltration in Posteriorly Worn Glenoids in Primary Glenohumeral Osteoarthritis: An MRI-based Study.

CORR Insights®: Imbalance in Axial-plane Rotator Cuff Fatty Infiltration in Posteriorly Worn Glenoids in Primary Glenohumeral Osteoarthritis: An MRI-based Study.

Características clínicas de la valoración fisioterapéutica en pacientes con síndrome subacromial

Background and objectiveOften the therapeutic results of patients diagnosed with subacromial syndrome who attend physiotherapy treatment are questioned. The aim of this study is to obtain epidemiological data that will allow a more effective evaluation and thus an improved treatment protocol. Material and methodsA cross-sectional descriptive observational study was carried out with 19 subacromial syndrome patients at a primary care medical centre of the Central University Hospital of Asturias (area IV). Postural aspects, scapular mobility, and shoulder apparatus (Constant-Murley Score) as well as their myofascial trigger points were explored and evaluated. ResultsThe subjects of the sample presented functional limitations of the shoulder affecting their activities of daily living and associated pain (51.7/75 Constant-Murley Score). Some 40% of the patients had limits to all their scapular movements and antalgic flexion positions and more than 70% presented trigger points, the infraspinatus muscle being the most prevalent (94.7%). ConclusionsResults suggest that myofascial trigger points in the shoulder apparatus, posture and scapular movement should be evaluated before physiotherapy treatment protocols for patients with subacromial syndrome are designed.

Imbalance in Axial-plane Rotator Cuff Fatty Infiltration in Posteriorly Worn Glenoids in Primary Glenohumeral Osteoarthritis: An MRI-based Study.

Imbalance in Axial-plane Rotator Cuff Fatty Infiltration in Posteriorly Worn Glenoids in Primary Glenohumeral Osteoarthritis: An MRI-based Study.

All-Arthroscopic Muscle Slide and Advancement Technique to Repair Massive Retracted Posterosuperior Rotator Cuff Tears

Symptomatic massive posterosuperior rotator cuff tears without glenohumeral joint arthritis and chronic medial retraction often are deemed “irreparable.” These patients often are treated with alternative joint-sparing procedures including superior capsular reconstruction or tendon transfer procedures. Open and arthroscopic-assisted muscle advancement techniques allow maximal lateral tendon mobilisation during rotator cuff repair. In this report, we present an all-arthroscopic technique of complete supraspinatus and infraspinatus muscle scapular detachment and advancement in retracted massive posterosuperior rotator cuff tears. This allows for an anatomical tendon footprint reduction and tension-free repair.

Effects of Conditioned Pain Modulation on Spread of Hyperalgesia after Intramuscular Capsaicin in Humans

Muscle pain can be associated with altered central pain processing, leading to hyperalgesia both locally and at distant body sites. The role of endogenous inhibitory mechanisms in hyperalgesia associated with muscle pain remains unclear. This study investigated the influence of conditioned pain modulation (CPM) on hyperalgesia at multiple body sites induced by intramuscular injection of capsaicin in the supraspinatus muscle. Thirty healthy males underwent CPM testing using the cold pressor test as conditioning stimulus and pressure pain threshold (PPT) as test stimulus. Muscle pain and hyperalgesia were induced by injection of capsaicin into the non-dominant supraspinatus muscle. Before and 5, 10, 15, 20, 30, 40, 50 and 60 min later, PPTs were recorded bilaterally at the supraspinatus, infraspinatus and deltoid muscles, ring finger and toe. Subjects were classified as inhibitory vs. facilitating CPM based on published reference values. Compared to baseline, PPTs decreased significantly at the supraspinatus, infraspinatus and deltoid muscle (p

Suprascapular Nerve Entrapment at the Spinoglenoid Notch By A Ganglion Cyst

Suprascapular nerve entrapment at the spinoglenoid notch by a ganglion cyst results in the paralysis of the terminal motor branch of the nerve, with isolated atrophy of the infraspinatus muscle, loss of strength in external rotation, and posterior shoulder pain. Increased awareness of this nerve compression is paramount in order to avoid the stage of irreversible infraspinatus muscle wasting and long term disability. Magnetic resonance imaging scan, electromyography and nerve conduction velocity studies can confirm the diagnosis and lead to an early arthroscopic nerve decompression and favorable functional results. We present a rare case of spinoglenoid ganglion cyst compression of the distal suprascapular nerve and discuss the recent developments in anatomy, aetiology, diagnosis, and review the treatment and current trends in the management of this condition.

Surgical Technique: Lower Trapezius Transfer in Paediatric Paralytic Shoulder.

The therapeutic management of the paralytic shoulder after an obstetric brachial plexus injury is complex. When nerve repair or neurotization fail, or if the biological times for nerve reconstruction is over, tendon transfer to restore active external rotation of the shoulder becomes the main surgical alternative. The purpose of this manuscript is to describe the surgical technique of the lower trapezius muscle transfer to the infraspinatus muscle, to restore active shoulder external rotation in the child with paralytic shoulder, step by step with details and pearls.

Meat quality, post-mortem proteolytic enzymes, and myosin heavy chain isoforms of different Thai native cattle muscles.

ObjectiveThis study investigated the meat quality characteristics, endogenous proteolytic enzymes, collagen content, and myosin heavy chain (MyHC) isoforms of different muscles of Thai native cattle (TNC).MethodsInfraspinatus (IF), Longissimus thoracis (LT), and Supraspinatus (SS) muscles were obtained from two TNC breeds, Kho-Lan (KL, n = 7) and Kho-Isaan (KI, n = 7). The muscle and meat characteristics of TNC breeds and their relationship with MyHC expression were examined.ResultsThree MyHC isoforms namely MyHC I, MyHC IIa, and MyHC IIx were detected in the muscles. The KL had higher (p<0.05) MyHC IIx than the KI. The IF muscle had higher (p<0.05) MyHC I compared to other muscles. The LT muscle had the least MyHC I. The LT had higher (p<0.05) MyHC IIx than the IF and SS muscles. The IF presented the least MyHC IIx. The KL had higher (p<0.05) lightness and moisture content and lower crude protein, redness, cooking loss, shear force, and calpastatin than the KI. The glycogen, total collagen, soluble collagen, crude protein, ash contents, and troponin T degradation product of IF and SS were lower (p<0.05) than that of LT. Ether extract in LT was lower (p<0.05) than that of IF and SS. The percentage of MyHC I, MyHC IIa, and MyHC IIx were significantly correlated with muscle and meat characteristics of TNC.ConclusionThese results suggest that the differences in the MyHC isoforms may partly account for the variation in meat quality between breeds and among muscles of TNC.

Immediate decrease of muscle biomechanical stiffness following dry needling in asymptomatic participants

BackgroundBiomechanical muscle stiffness has been linked to musculoskeletal disorders. Assessing changes in muscle stiffness following DN may help elucidate a physiologic mechanism of DN. This study characterizes the effects of dry needling (DN) to the infraspinatus, erector spinae, and gastrocnemius muscles on biomechanical muscle stiffness. Method60 healthy participants were randomized into infraspinatus, erector spinae, or gastrocnemius groups. One session of DN was applied to the muscle in standardized location. Stiffness was assessed using a MyotonPRO at baseline, immediately post DN, and 24 h later. The presence of a localized twitch response (LTR) during DN was used to subgroup participants. ResultsA statistically significant decrease in stiffness was observed in the gastrocnemius, the LTR gastrocnemius, and the LTR erector spinae group immediately following DN treatment. However, stiffness increased after 24 h. No significant change was found in the infraspinatus group. ConclusionsDN may cause an immediate, yet transitory change in local muscle stiffness. It is unknown whether these effects are present in a symptomatic population or related to improvements in clinical outcomes. Future studies are necessary to determine if a decrease in biomechanical stiffness is related to improvement in symptomatic individuals.

Locating the rotator cable during subacromial arthroscopy: bursal- and articular-sided anatomy.

The rotator cable (RCa) is an important articular-sided structure of the cuff capsular complex that helps prevent suture pull out during rotator cuff repairs (RCRs) and plays a role in force transmission. Yet, the RCa cannot be located during bursal-sided RCRs. The purpose of this study is to develop a method to locate the RCa in the subacromial space and compare its bursal- and articular-sided dimensions. In 20 fresh-frozen cadaveric specimens, the RCa was found from the articular side, outlined with stitches, and then evaluated from the bursal side using an easily identifiable reference point, the intersection of a line bisecting the supraspinatus (SS) tendon and posterior SS myotendinous junction (MTJ). Four bursal-sided lengths were measured on the SS-bisecting line as well as the RCa's outside anteroposterior base. For the articular-sided measurements, the rotator cuff capsular complex was detached from bone and optically scanned creating 3D solid models. Using the 3D models, 4 articular-sided lengths were made, including the RCa's inside and outside anteroposterior base. The RCa's medial arch was located 9.9 ± 5.6 mm from the reference point in 10 intact specimens and 4.1 ± 2.4 mm in 10 torn specimens (P = .007). The RCa's width was 10.9 ± 2.1 mm, and the distance from the lateral edge of the RCa to the lateral SS insertion was 13.9 ± 4.8 mm. The bursal- and articular-sided outside anteroposterior base measured 48.1 ± 6.4 mm and 49.6 ± 6.5 mm, respectively (P = .268). The average inside anteroposterior base measurement was 37.3 ± 5.9 mm. The medial arch of the RCa can be reliably located during subacromial arthroscopy using the reference point, analogous to the posterior SS MTJ. The RCa is located 10 mm in intact and 4 mm in torn tendons (P = .007) from the posterior SS MTJ. If the above 6-mm shift in location of the RCa is not taken into consideration during rotator cuff suture placement, it could negatively affect time zero repair strength. The inside anteroposterior base of the RCa measures on average 37 mm; therefore, rotator cuff tears measuring >37 mm are at risk of rupturing part or all of the RCa's 2 humeral attachments, which if not recognized and addressed could impact postoperative function.

Use of Gracile and semi-tendinosus tendons (GRAST) for the reconstruction of irreparable rotator cuff tears

BackgroundIrreparable rotator cuff tears are common and difficult to treat. Techniques for “filling the loss of substance” require fixation to the rotator cuff stump (tendon augmentation) or to the glenoid (superior capsular reconstruction), which are complicated by the narrow working zone of the subacromial space. The main objective of this study was to determine whether a braided graft of gracilis (GR) and semitendinosus (ST) could fill a loss of tendon substance from an irreparable rupture of the supra- and infraspinatus, by fixing the graft to the greater tuberosity and the spine of the scapula.MethodsThis was a cadaveric study with the use of ten specimens. The GRA and ST tendons were harvested, braided and reinforced with suture. An experimental tear of the supraspinatus (SS) and upper infraspinatus (IS) retracted at the glenoid was made. The GRAST transplant was positioned over the tear. The transplant was attached to the greater tuberosity by two anchors and then attached to the medial third of the scapular spine by trans-osseous stitching. The percentage of filling obtained was then measured and passive mobility of the shoulder was assessed. We proceeded to the same technique under arthroscopy for a 73 years old patient whom we treated for a painful shoulder with irreparable cuff tear. We inserted a GRAST graft using arthroscopy.ResultsThe Braided-GRAST allowed a 100% filling of the loss of tendon substance. Mobility was complete in all cases.ConclusionThis technique simplifies the medial fixation and restores the musculo-tendinous chain where current grafting techniques only fill a tendinous defect. The transplant could have a subacromial “spacer” effect and lower the humeral head. The donor site morbidity and the fate of the transplant in-vivo are two limits to be discussed. This anatomical study paves the way for clinical experimentation.

Stiffness of the infraspinatus and the teres minor muscles during shoulder external rotation: An in-vitro and in-vivo shear wave elastography study

BackgroundA better understanding of the morphological and functional differences in the anatomical sub-regions of the rotator cuff muscles is critical so that appropriate surgical and rehabilitation methodologies can be implemented in patients with shoulder-related injuries. The purpose of the current study was to develop a comprehensive imaging protocol using shear-wave elastography for the infraspinatus and teres minor muscles, and investigate differences in elastic properties of three distinct infraspinatus muscle sub-regions and of the teres minor muscle. MethodsFirst, we developed a protocol for probe positioning for both muscles using three cadaveric shoulders. Second, we evaluated in-vivo elastic properties [passive and active stiffness (kPa)] and excursion (mm) outcomes from these muscles during shoulder external rotation. FindingsElastic properties were significantly different among the infraspinatus muscle sub-regions and teres minor muscle. Passive stiffness decreased with increasing rotation angles except for the middle sub-region of the infraspinatus muscle which showed a decreased up to mid-range followed by an increment towards the end-range. Overall, active stiffness of the infraspinatus muscle and teres minor muscle decreased with increasing rotation angles, while that of the middle sub-region increased up to mid-range, and decreased at the end-range. InterpretationDistinct characteristics of the infraspinatus and teres minor muscles, and more importantly, of the individual sub-regions within the infraspinatus muscle call for an in-depth analysis of their morphological and functional differences. Special attention should be put into these sub-regions when performing surgical and rehabilitation procedures for patients with shoulder-related injuries.

Outcomes after rotational infraspinatus muscle transfer for irreparable massive rotator cuff tears and long-term follow-up

We developed a surgical technique for rotational infraspinatus muscle transfer in cases with irreparable massive rotator cuff tears while avoiding strong tension at the repaired site to avoid causing paralysis of the suprascapular nerve. Our method involves detaching the infraspinatus muscle, including the portion where the infraspinatus and supraspinatus muscles are connected to the scapula. With this rotational transfer of the infraspinatus muscle, reconstructions of the damaged infraspinatus and supraspinatus muscles are possible by elongation of the supraspinatus muscle.

Characterization of Infraspinatus Tendon Anatomy: The Soft-Tissue Portion of Remplissage

PurposeTo characterize the morphology of the infraspinatus (IS) tendon and evaluate the bony anatomy of the humeral head (HH) to determine if there is a correlation between HH measurements and the amount of available IS tendon.MethodsThe superior-inferior width as well as the medial-lateral (M-L) length of the inferior and superior portions of the IS tendon were measured in 15 human cadaveric shoulders. Three measurements were then obtained for each corresponding humeral head: (1) anterior to posterior (A-P) distance, (2) midcoronal humeral head distance (MCHH), and (3) M-L distance. Pearson correlation coefficients (R) of tendon measurements relative to HH measurements were determined.ResultsThe mean ± SD HH measurements were 44.3 ± 3.3 mm for A-P, 49.3 ± 3.4 mm at the MCHH, and 52.2 ± 3.4 mm in the M-L plane. The mean M-L length of the superior portion of the IS tendon was significantly different from the inferior portion (42.4 vs 31.0 mm, P < .0001). The mean ± SD width of the IS tendon was 19.4 ± 3.0mm. There was a statistically significant correlation (R = 0.58) between the M-L length of the superior IS tendon relative to the M-L HH distance (P < .05) and the A-P HH distance (P < .05).ConclusionsThe superior M-L IS tendon length was significantly greater than the inferior M-L length. The M-L HH and the AP HH distances were significantly correlated to the M-L length of the superior portion of the IS tendon. These relationships may provide an estimation of the length of available IS tendon to help guide the management of Hill-Sachs lesions (HSLs).Clinical RelevanceKnowledge of the available IS length can help optimize the management of HSLs following anterior shoulder dislocation. If IS tendon M-L length is less than HSL M-L length, then remplissage may result in capsulomyodesis rather than tenodesis. Placement of the superior anchor in a position that is as superior as possible within the HSL defect will maximize the opportunity for IS tenodesis.

Muscle volume imbalance may be associated with static posterior humeral head subluxation

BackgroundThe transverse force couple (TFC) of the rotator cuff (subscapularis vs. infraspinatus and teres minor muscle) is an important dynamic stabilizer of the shoulder joint in the anterior-posterior direction. In patients with posterior static subluxation of the humeral head (PSSH), decentration of the humeral head posteriorly occurs, which is associated with premature arthritis. We hypothesize that not only pathologic glenoid retroversion but also chronic muscle volume imbalance in the transverse force couple leads to PSSH.MethodsA retrospective analysis of the TFC muscle volumes of 9 patients with symptomatic, atraumatic PSSH, within 8 were treated with glenoid correction osteotomy, was conducted. The imaging data (CT) of 9 patients/10 shoulders of the full scapula and shoulder were analyzed, and the muscle volumes of the subscapularis (SSC), infraspinatus (ISP) and teres minor muscles (TMM) were measured by manually marking the muscle contours on transverse slices and calculating the volume from software. Furthermore, the glenoid retroversion and glenohumeral distance were measured.ResultsThe mean glenoid retroversion was − 16° (− 7° to − 31°). The observed mean glenohumeral distance was 4.0 mm (0 to 6.8 mm). Our study population showed a significant muscle volume imbalance between the subscapularis muscle and the infraspinatus and teres minor muscles (192 vs. 170 ml; p = 0.005). There was no significant correlation between the subscapularis muscle volume and the glenohumeral distance (r = 0.068), (p = 0.872).ConclusionThe muscle volume of the SSC in patients with PSSH was significantly higher than the muscle volume of the posterior force couple (ISP and TMM). This novel finding, albeit in a small series of patients, may support the theory that transverse force couple imbalance is associated with PSSH.Level of evidenceLevel 4 – Case series with no comparison group.

Electromyographic Evaluation of the Shoulder Muscle after a Fatiguing Isokinetic Protocol in Recreational Overhead Athletes.

The goal of our study was to examine the muscle activity of the shoulder girdle after isokinetic fatigue, which may simulate muscle activities commonly occurring during specific sport-related activities in recreational overhead asymptomatic athletes. We hypothesized that exercise-induced fatigue, reported after isokinetic protocols, may cause a decrease in the median frequency (MF) of the upper trapezius (UT), infraspinatus (IS), and deltoid muscles. Twenty-four male overhead volleyball (n = 8), handball (n = 8), and tennis (n = 8) athletes participated in this study. All subjects were without shoulder injury history. The surface electromyography (SEMG) was collected on the right (dominant) side of the shoulder girdle muscles in the following order: UT, IS and anterior (DA), and posterior deltoideus (DP). The fatigue protocol consisted of three sets of 32 maximum isokinetic concentric contractions while performing shoulder internal and external rotation at an isokinetic speed of 120 o/s. The resultant difference in median frequency (ΔMF) values consistently dropped after the fatiguing tasks across all recorded muscles, in terms of the initial MF (MFINI = 65.1 ± 1.1 Hz) and final MF (MFFIN = 57.9 ± 0.9 Hz), and the main effect of time was significant (F(1,22) = 43.15, p < 0.001). MF values decreased mostly for IS (ΔMFIS = −9.9 ± 1.6 Hz) and DP (ΔMFPD = −9.5 ± 1.9 Hz) muscles, while DA and UT showed smaller changes (ΔMFDA = −6.9 ± 1.5 Hz) and (ΔMFUT = −3.2 ± 1.3 Hz). The results of our study show a meaningful contribution in determining increased fatigue of the shoulder girdle muscles during repeated isokinetic internal-external rotation protocols. We have also demonstrated a significant decrease in MF in all examined muscles, especially IS and DA.

Prevalence of Cervical Myofascial Pain Syndrome and its Correlation with the Severity of Pain and Disability in Patients with Chronic Non-specific Neck Pain.

Nonspecific chronic neck pain is increasing according to work-related gestures and modern lifestyle. Myofascial pain syndrome is a common problem and may be a primary disease. This study was designed to evaluate the prevalence of cervical myofascial pain syndrome in patients with chronic non-specific neck pain with normal MRI. We also examined the correlation between patients' age as well as pain severity and duration. Patients with neck pain radiating to their upper extremity were examined despite normal MRI findings. We evaluated 10 different muscles based on myofascial pain syndrome criteria and also recorded pain intensity and functional ability using visual analogue scale and neck disability index, respectively. A physical therapist with at least 10 years of clinical experience with myofascial pain syndrome performed all physical examinations. A total of 126 patients (69 females and 57 males) participated in this study, out of whom, 14 patients (11.1%) had no muscular involvement, while 112 cases (88.9%) revealed at least one trigger point. The infraspinatus and scalene muscles were the most commonly involved muscles accounting for 38.9% and 34.9% of all the involvements, respectively. The severity of pain was significantly associated with the disability of the patients (r=0.64, P<0.001). However, the correlation between pain and the number of trigger points was not significant (r=-0.19, P=0.31). Finally, the least significantly correlated variables were disability and the number of trigger points (r=-0.17, P=0.05). Patient's age was significantly correlated neither with the number of trigger points (r=-0.04, P=0.62), nor the pain duration (r=0.07, P=0.39). Myofascial pain syndrome is a common disorder in patients with nonspecific chronic neck pain, despite normal MRI findings. Although, pain is not correlated with the number of trigger points in these patients, we demonstrated a small correlation between patients' disability and the latter variable.

L-Shaped Arthroscopic Posterior Capsular Release in Frozen Shoulder

Background: The inadequate arthroscopic release of the tight posterior capsule in frozen shoulder may result in limited postoperative shoulder internal rotation. Indication: The purpose of this article is to describe an L-shaped arthroscopic posterior capsular release to overcome the limited internal rotation that may be encountered following the standard longitudinal technique. Operative intervention is indicated in patients with refractory shoulder stiffness with limitation of internal rotation of grade 0, +2, +4 (according to the Constant-Murley Score), after failure of conservative measures for 3 to 6 months. The technique is contraindicated if less than 3 months of physical therapy, shoulder stiffness due to osseous deformity, infection, or cuff tear arthropathy. Technique: After performing a standard anterior capsular release, the scope is shifted to the anterior portal to perform posterior capsular release by introducing the radiofrequency ablation device through the posterior portal. Posterior release begins from the glenoid level down to the 6 o’clock position until the back fibers of the infraspinatus muscle appear. Then the hook-tip part of the radiofrequency ablation device is used to perform a transverse release in the posterior capsule, starting from the beginning of the longitudinal limb. The transverse limb is performed in a stepwise manner going step-by-step laterally but ending before reaching the rotator cuff to avoid any damage of the cuff. After that, the shoulder was manipulated according to Codman technique. Results: A comparative study was performed on 43 patients with primary frozen shoulder to compare the standard longitudinal (22 patients) and L-shaped (21 patients) posterior capsular release. At the final follow-up, there was a statistically significant improvement in the internal rotation range of motion in the L-shaped group ( P &lt; .001). There was no loss of function over time. Moreover, there were no infections, instability, or axillary nerve injury in either group. Discussion/Conclusion: Restriction of internal rotation in frozen shoulder has been attributed to posterior capsular tightness. The L-shaped arthroscopic posterior capsular release in patients with primary frozen shoulder significantly improves the postoperative internal rotation range of motion.

A study on the immediate effects of neuromuscular electrical stimulation on the corticospinal tract excitability of the infraspinatus muscle

Rotator cuff muscles are structurally and functionally different from other upper-limb muscles because they are responsible for glenohumeral joint stability. Neuromuscular electrical stimulation (NMES) induces excitability changes (increase or decrease) of the corticospinal tract (CST) in the peripheral muscles, such as those of the finger. However, it remains unclear whether similar results are obtained when targeting the infraspinatus muscle, which has properties that differ from other muscles, in healthy subjects. We investigated the immediate effects of NMES on the corticospinal excitability of the infraspinatus muscle, a rotator cuff muscle, in healthy subjects. Thirteen healthy right-handed men (mean age: 26.77 ± 2.08 years) participated in this study. The motor evoked potentials (MEPs) and the maximum compound muscle action potential (Mmax) were recorded before NMES to the right infraspinatus and within 15 minutes after the end of the NMES. NMES on the infraspinatus muscle significantly increased its MEP amplitude (Pre: 0.45 mV [0.33-0.48]; Post: 0.54mV [0.46-0.60] (median [lower quartile to higher quartile]); p= 0.005) but had no effect on Mmax (Pre: 2.95 mV [2.59-4.71]; Post: 3.35 mV [2.76-4.72]; p= 0.753). NMES application to the infraspinatus muscle increases CST excitability without producing immediate changes in the neuromuscular junction or muscle hypertrophy.