Biceps Disorder Rehabilitation for the Athlete: A Continuum of Moderate- to High-Load Exercises

All-Arthroscopic Falciform Portal Biceps Tenodesis

Biceps tenodesis has been proven to be an effective treatment for biceps tendon and superior labral pathology. Many techniques including both open and arthroscopic approaches have been reported. Open techniques afford management of the entire proximal biceps tendon but are limited by wound healing issues, increased bleeding, and increased surgical time. Arthroscopic tenodesis offers benefits in terms of surgical efficiency, cosmesis, and bleeding risk. However, standard arthroscopic tenodesis only addresses intra-articular biceps pathology. In this report we describe an all-arthroscopic biceps tenodesis technique at the suprapectoral region of the humerus using knotless suture anchor fixation.

The long head of biceps at the shoulder: a scoping review

BACKGROUND

This review aimed to explore the available literature to update our understanding of the long head of biceps (LHB) at the shoulder. Synthesise our findings to identify emergent themes and knowledge gaps to inform future research and management directions.

METHODS

PubMed, Embase, Cinahl, SportDiscus, CENTRAL, and Web of Science were searched from inception to 31st December 2021. Articles were included if they referenced adult participants > 18 years of age and were written in English.

RESULTS

214 articles were included in the final analysis, and results were categorised into six emergent themes: (1) Anatomy - Normal anatomical variation of the biceps from aberrant origins, third and fourth accessory heads, and an absence of the LHB tendon (LHBT) are not necessarily benign, with shoulder pain and instability a commonly reported theme. (2) Function - Bicep's role in glenohumeral elevation and stability in healthy shoulders is minimal. In contrast, LHB has a more significant role in shoulder stability and humeral head depression in subjects with rotator cuff failure or an absent LHBT. (3) Pathology - There is an association between LHB tendinopathy, rotator cuff disease, LHBT instability and occult rotator cuff tears. Early recruitment and hyperactivity of the LHB in subjects with symptomatic rotator cuff tears and instability suggest a potential compensatory role. (4) Assessment - The limited diagnostic utility of special orthopaedic tests in assessing LHBT pathology was a consistent theme. The utility of magnetic resonance imaging and ultrasound to identify full-thickness tendon tears and instability of the LHBT was moderate to high. However, the utility of clinical tests and imaging may be underestimated due to arthroscopy's limitations in fully visualising the proximal LHBT. (5) Non-Surgical Management - Ultrasound-guided injections into the biceps sheath show greater accuracy and patient outcomes than blinded injections; however, the entry of injectate into the intraarticular glenohumeral joint may have unwanted complications. (6) Surgical management - For the surgical management of biceps pathology with or without rotator cuff pathology, both biceps tenodesis and tenotomy report similar improvements in pain without any significant adverse effect on strength or function. Tenodesis favoured higher overall constant scores and a lower incidence of Popeye deformity and cramping arm pain, with tenotomy trending to be more cost and time effective. For patients with a healthy LHBT, rotator cuff repair with adjunctive tenodesis or tenotomy fails to provide additional clinical improvements compared to rotator cuff repair in isolation.

CONCLUSIONS

The scoping review highlights the variability of biceps anatomy, which is not necessarily benign and suggests a minimal role of the LHB in shoulder elevation and stability in healthy individuals. In contrast, individuals with rotator cuff tears experience proximal humeral migration and demonstrate hyperactivity of the LHB, suggesting a potential compensation role. The observed prevalence of LHBT pathology with rotator cuff tears is well established; however, the cause-and-effect relationship between LHBT pathology and rotator cuff disease is undetermined. The diagnostic utility of clinical tests and imaging to exclude LHBT pathology may be understated due to the limitations of arthroscopy to visualise the proximal LHBT fully. Rehabilitation programs for the LHB are understudied. Similar post-surgical clinical outcomes are observed for tenodesis and tenotomy for biceps and rotator cuff-related shoulder pain. Subjects undergoing biceps tenodesis are less likely to have cramping arm pain and a Popeye deformity than patients undergoing biceps tenotomy. The significance of routine surgical removal of the LHBT and sequelae on rotator cuff tear progression to failure and long-term shoulder function is unknown, and further research is required.

PRE-REGISTRATION

OSF: https://osf.io/erh9m.

Biceps Brachii and Brachioradialis Excitation in Biceps Curl Exercise: Different Handgrips, Different Synergy

The current study analyzed the excitation of biceps brachii, brachioradialis, and anterior deltoid during bilateral biceps curl performed with different handgrips. Ten competitive bodybuilders performed bilateral biceps curl in non-exhaustive 6-rep sets using 8-RM with the forearm in supinated, pronated, and neutral positions. The ascending and descending phase of each variation was separately analyzed using the normalized root mean square collected using surface electromyography. During the ascending phase, (i) biceps brachii excitation was greater with the supinated compared to the pronated [+19(7)%, ES: 2.60] and neutral handgrip [+12(9)%, ES: 1.24], (ii) the brachioradialis showed greater excitation with the supinated compared to the pronated [+5(4)%, ES: 1.01] and neutral handgrip [+6(5)%, ES: 1.10], (iii) the anterior deltoid excitation was greater with the pronated and neutral handgrip compared to the supinated condition [+6(3)% and +9(2)%, ES: 2.07 and 3.18, respectively]. During the descending phase, the anterior deltoid showed greater excitation in the pronated compared to the supinated handgrip [+5(4)%, ES: 1.02]. Changing the handgrips when performing biceps curl induces specific variations in biceps brachii and brachioradialis excitation and requires different anterior deltoid interventions for stabilizing the humeral head. Practitioners should consider including different handgrips in the biceps curl routine to vary the neural and mechanical stimuli.

Muscle activity with 0.5 T upright MRI-DESS to measure T2 in biceps and triceps

The purpose of this study was to determine if muscle activity of the biceps followed by isometric flexion changes T₂ measured in the biceps. It is hypothesized that an increase in T₂ will be observed in the biceps but not in the triceps after flexion exercise. Ten healthy volunteers were imaged with a one-channel neck coil while seated in a 0.5 T upright open magnetic resonance imaging (MRI) scanner using a three-dimensional double echo steady-state (DESS) sequence. Volunteers were imaged while relaxing their arm for 10, 20, and 30  min during an isometric biceps flexion immediately following performance of biceps curls to exhaustion, and again after relaxing for 10 and 20 min. Voxel-wise T₂ was calculated by fitting to a DESS signal equation in regions segmented at muscle centers to determine mean T₂ . During isometric biceps flexion immediately following biceps curls, mean T₂ increased (average 33%, p < 0.05) in the biceps but not in the triceps. By 20 min after curls, mean T₂ decreased (p < 0.05), and was near preactivity values. In contrast, there was no change in triceps T₂ across any activity or postactivity time points. Intra-rater repeatability was excellent (ICC: 0.90-0.97). This study demonstrated that measuring T₂ in an active muscle is feasible using a DESS sequence in an upright open MRI scanner. This could enable the study of muscle function while the muscle is working and weight-bearing, rather than of the "fatigue" of the muscles after activity. In comparison to electromyography, MRI also enables the study of deep muscles and allows simultaneous assessment of activity and function.

Rehabilitation Exercises for Dysfunction of the Scapula: Exploration of Muscle Activity Using Fine-Wire EMG

BACKGROUND

Scapular muscle activity during shoulder exercises has been explored with surface electromyography (EMG). However, knowledge about the activity of deeper-layer scapular muscles is still limited.

PURPOSE

To investigate EMG activation of the deeper-layer scapular stabilizers (levator scapulae [LS], rhomboid major [RM], pectoralis minor [Pm] muscles) together with superficial muscle activity (upper [UT], middle [MT], and lower trapezius [LT] and serratus anterior [SA]) during 4 exercises often used for training scapular function. Based on the amplitude EMG of the deeper-layer muscles, scapular muscle activation ratios for the 4 exercises were calculated, hereby providing knowledge of the optimal muscle balance.

STUDY DESIGN

Descriptive laboratory study.

METHODS

A total of 26 healthy participants performed 4 shoulder exercises (side-lying external rotation [ER], side-lying forward flexion, prone horizontal abduction with ER, and prone extension) while simultaneously measuring scapular muscle activity. Intramuscular electrodes were used for the deeper layer, in contrast to surface electrodes for the superficial muscles. All data were normalized to percentage of maximal voluntary isometric contraction (%MVIC), and the activation ratios (the muscle activity of the deeper layer relative to the other muscles) were calculated. A 1-way analysis of variance with Bonferroni correction was applied for statistical analysis.

RESULTS

Moderate activity was found in all exercises for the LS and RM (25%-45% MVIC). The Pm resulted in low activity during both side-lying exercises (13%-18% MVIC). Ratios involving LS or RM showed values >1 for all exercises (1.28-12.41) except for LS/MT, LS/LT, and LS/RM (0.85-0.98) during side-lying ER, and LS/MT, RM/MT and RM/LS (0.85-0.99) during side-lying forward flexion. Likewise, values <1 were found when MT (0.85) and LS (0.99) were involved with RM in the numerator during side-lying forward flexion. Ratios with Pm in the numerator showed values <1, apart from the ratios with UT and SA in the denominator.

CONCLUSION

The study provides extended knowledge about the deeper-layer scapular muscle activity and related ratios during the 4 shoulder exercises mentioned here. Putting theory into practice, based on our results, we advise both side-lying exercises to be performed to strengthen LT and MT, even in case of hyperactivity of the Pm. However, the 4 exercises should be given carefully to patients with hyperactivity in the LS and/or RM.

CLINICAL RELEVANCE

The findings of this study may assist clinical decision making in exercise selection for restoring scapular function.

[Rehabilitation of patients after surgical treatment of avulsion rupture of the distal biceps brachial tendon]

Avulsion subcutaneous rupture of the distal tendon of the biceps brachial is a relatively rare occurrence. In the context of postoperative treatment, there are isolated references to rehabilitation therapists and sports physicians in the literature. However, the popularization of sports among the general population forces specialists to face this problem in clinical practice. The objective of the presented study was to review our own concept of rehabilitation in the early and late postoperative periods using the example of a specific clinical case of surgical treatment using fixation with a cortical button and an interference screw in trauma in a professional athlete. A group of surgeons and rehabilitation therapists focused their efforts on returning the patient to normal amplitudes of movements in the joints of the injured limb the ability to endure previous loads without pain in the shortest possible time without fear of relapse. The results obtained during the treatment of a sports-organized patient with an avulsion rupture of the distal tendon of the biceps brachial made it possible to question the success of the previous «immobilization» concepts broadened the professional understanding of the possibilities of modern rehabilitation allowed surgeons and rehabilitation therapists to come close to developing a universal rehabilitation protocol form.

Optimal activation ratio of the scapular muscles in closed kinetic chain shoulder exercises: A systematic review

BACKGROUND

Muscle synergies contribute to scapular position during arm movement. The trapezius and serratus anterior (SA) muscles are the main stabilizers and are therefore the main target muscles of therapeutic exercises.

OBJECTIVE

To systematically review the current literature investigating the optimal activation ratio of the scapular muscles during a range of closed kinetic chain exercises.

METHODS

A systematic review search was conducted to identify studies reporting shoulder electromyography (EMG) activity during rehabilitation exercises in healthy participants. The search was conducted in PubMed, Cochrane Library, MEDLINE, CINAHL, Scopus, SPORTDiscus, and ScienceDirect. The included studies reported closed kinetic chain exercises and the muscle activity as a percentage of maximum voluntary isometric contraction (%MVIC) or muscle ratios of the lower trapezius (LT), middle trapezius (MT), and SA with respect to the upper trapezius (UT). Muscle ratios were classified as optimal if they were equal to or lower than 0.6, and the adapted Newcastle-Ottawa Scale (NOS) was used to evaluate the methodological quality of the selected studies.

RESULTS

Twenty-nine studies were included in this review; 7 main exercises and 30 variations of these were reported. The average electromyographic activity of the concentric and eccentric phase was considered. Half Push Up, Push Up Plus, and Scap Protraction exercises showed optimal SA activity (UT/SA < 0.6), while Press Up, Half Push Up, and One Hand Plank exercises showed optimal LT activity (UT/LT < 0.6). According to the NOS, 15 studies were classified as moderate methodological quality.

CONCLUSIONS

The exercises in higher positions (e.g. exercises with the trunk closest to the vertical line) or unstable surfaces tend to favor UT activity over the MT, LT and SA. The exercises including scapular retraction showed optimal UT/MT and UT/LT ratios, while those including scapular protraction showed optimal UT/SA ratios. This will assist therapists in the correct selection of exercises for shoulder rehabilitation.

Does the Activity in Scapular Muscles During Plyometric Exercises Change When the Kinetic Chain Is Challenged?-An EMG Study

Werin, MB, Maenhout, AG, Icket, J, Jacxsens, N, Kempkes, E, and Cools, AM. Does the activity in scapular muscles during plyometric exercises change when the kinetic chain is challenged?-An EMG study. J Strength Cond Res XX(X): 000-000, 2020-Plyometric exercises for the shoulder are used in rehabilitation and in workout regime when the sport demands high speed power training. The aim of this clinical laboratory electromyography (EMG) study was to determine whether scapular muscle performance differs during plyometric shoulder exercises when changing the demand on the kinetic chain. Thirty healthy overhead athletes, with a mean age of 22.7 years (±2.2), performed 6 exercises, with both a low and a high demand on the kinetic chain, in prone, side and standing in positions. The EMG activity of the upper trapezius (UT), middle trapezius (MT), lower trapezius (LT), and serratus anterior (SA) on the tested side and bilateral of gluteus maximus (GM) and abdominal oblique externus (OE) was registered with wireless surface EMG. Intermuscular muscle ratios UT/SA, UT/MT, and UT/LT were also calculated. The level of significance set for the study was alpha = 0.05. The muscle ratio UT/SA was significantly lower (p < 0.05) when high demand on the kinetic chain compared with low. SA muscle activity showed significantly (<0.001) higher values in the prone position with high demand on the kinetic chain compared with low. All 3 trapezius muscle parts had significantly higher values (p < 0.001) in the prone compared with side and standing positions. The GM and OE showed significantly higher (p ≤ 0.01) activity in positions more demanding for the kinetic chain. When composing a strengthening or a rehabilitation program for athletes, the knowledge of how scapular and trunk muscles interact can be used to amplify the strengthening effect.

Electromyographic analysis of selected shoulder muscles during a series of exercises commonly used in patients with symptomatic degenerative rotator cuff tears

BACKGROUND

In the nonoperative treatment of degenerative rotator cuff (RC) tears, exercise therapy is advocated. Exercises focusing on strengthening the anterior deltoid (AD) and the scapular muscles are proposed to compensate for RC dysfunction. However, the amount of electromyographic (EMG) activity in these muscles during these exercises remains unclear. Moreover, it is unknown whether muscle activity levels during these exercises alter with increasing age. Therefore, the purpose of this study was to evaluate EMG activity in the deltoid and scapular muscles during 2 series of commonly used shoulder rehabilitation exercises and assess possible age-related changes in muscle activity.

METHODS

Fifty-five healthy participants (aged 18-60 years) participated in this study. Surface EMG activity was measured in 8 shoulder girdle muscles during a progression of a closed chain elevation program (bench and wall slides) and during a progression of previously published AD exercises. In addition, muscle activity was compared between 3 age categories (18-32 years, 33-46 years, and 47-60 years).

RESULTS

The proposed progressions exhibited increasing activity from <10% of maximal voluntary isometric contraction to >20% of maximal voluntary isometric contraction for the AD for both exercise programs and for the middle deltoid, upper trapezius, and middle trapezius during the closed chain elevation exercises. Activity levels in the other muscles remained <20% throughout the progression. Age-related analysis revealed increased activity in the AD, infraspinatus, and middle trapezius and decreased lower trapezius activity during the bench and wall slides. No age-related changes were noted for the AD exercises.

CONCLUSION

These findings may assist the clinician in prescribing appropriate progressive exercise programs for patients with symptomatic RC tears.

The challenge of the sporting shoulder: From injury prevention through sport-specific rehabilitation toward return to play

Shoulder injuries and sports-related shoulder pain are substantial burdens for athletes performing a shoulder loading sport. The burden of shoulder problems in the athletic population highlights the need for prevention strategies, effective rehabilitation programs, and a individually based return-to-play (RTP) decision. The purpose of this clinical commentary is to discuss each of these 3 challenges in the sporting shoulder, to assist the professional in: (1) preventing injury; (2) providing evidence-based practice rehabilitation and; (3) to guide the athlete toward RTP. The challenges for injury prevention may be found in the search for (the interaction between) relevant risk factors, develop valid screening tests, and implement feasible injury prevention programmes with maximal adherence from the athletes. Combined analytical and functional testing seems mandatory screening an athlete's performance. Many questions arise when rehabilitating the overhead athlete, from exercise selection, over the value of stretching, toward kinetic chain implementation and progression to high performance training. Evidence-based practice should be driven by the available research, clinical expertise and the patient's expectations. Deciding when to return to sport after a shoulder injury is complex and multifactorial. The main concern in the RTP decision is to minimize the risk of re-injury. In the absence of a "gold standard", clinicians may rely on general guidelines, based on expert opinion, regarding cutoff values for normal range of motion, strength and function, with attention to risk tolerance and load management.

Analysis of Scapular Kinematics and Muscle Activity by Use of Fine-Wire Electrodes During Shoulder Exercises

BACKGROUND

During nonoperative or postoperative rehabilitation after sports injuries, exercise selection is often based on minimal load on the injured/repaired glenohumeral structures, while optimally activating scapulothoracic muscles. Previous research explored scapular muscle activity during rehabilitation exercises using surface electromyography (EMG). However, limited information exists about the deeper lying muscle activity, measured with fine-wire electrodes, even more in combination with 3-dimensional scapular kinematics.

PURPOSE

To report scapular kinematics synchronously with surface and fine-wire EMG during specific shoulder exercises for early rehabilitation.

STUDY DESIGN

Descriptive laboratory study.

METHODS

A total of 23 healthy male patients were recruited. Three-dimensional scapular kinematics were measured combined with EMG recording of 8 muscles during 4 commonly used shoulder exercises (inferior glide, low row, lawnmower, and robbery). Upper (UT), middle (MT), and lower (LT) trapezius and serratus anterior muscle activities were measured with bipolar surface electrodes. Intramuscular electrodes were placed in the levator scapulae (LS), rhomboid major (RM), pectoralis minor (Pm), and infraspinatus (IS) muscles. All data were normalized as a percentage of maximal voluntary isometric contraction (%MVIC). A linear mixed model with Bonferroni correction was applied for statistical analysis.

RESULTS

Scapular kinematics revealed an anterior tilt position during the inferior glide, low row, and robbery (P < .05). An upward rotation position between 20° and 30° was reached in all exercises except low row. Inferior glide (31°) and low row (42°) represented a significantly increased internal rotation position compared with lawnmower and robbery. Lawnmower and robbery showed significantly (P < .05) more MT (lawnmower, 36% MVIC; robbery, 39% MVIC) and RM (lawnmower, 59% MVIC; robbery, 66% MVIC) activation compared with inferior glide and low row. Lawnmower and robbery showed significantly (P < .05) less Pm activation (9.5%-12% MVIC). LS was significantly more active during robbery (58% MVIC) compared with inferior glide and low row (27%-36% MVIC) (P < .05). IS showed moderate activity (24%-37% MVIC) for all exercises, except low row (13% MVIC).

CONCLUSION/CLINICAL RELEVANCE

This study provides new insights about scapular positions and activation of the deeper layer muscles during 4 commonly used shoulder rehabilitation exercises. The lawnmower showed a favorable position of the scapula with less Pm activity in contrast to the low row. The inferior glide, lawnmower, and robbery should not be implemented in early phases of shoulder rehabilitation because of their moderate muscle activity.

Incorporation of the Kinetic Chain Into Shoulder-Elevation Exercises: Does It Affect Scapular Muscle Activity?

CONTEXT

Scapular rehabilitation exercises should focus on selective activation of weaker muscles and minimal activation of hyperactive muscles. For rehabilitation of overhead athletes, single-plane open chain exercises below 90° of shoulder elevation are often recommended. Moreover, incorporating the kinetic chain in shoulder rehabilitation exercises is advised and has been suggested to influence scapular muscle activity levels.

OBJECTIVE

To study the influence of kinetic chain incorporation during 5 variations of a shoulder-elevation exercise on scapular muscle activity.

DESIGN

Cross-sectional study.

SETTING

University laboratory.

PATIENTS OR OTHER PARTICIPANTS

Thirty-one asymptomatic participants (15 men, 16 women).

MAIN OUTCOME MEASURE(S)

The electromyographic activity of the upper (UT), middle (MT), and lower (LT) trapezius, and serratus anterior was determined during 5 variations of bilateral elevation with external rotation: (1) open-hand position (reference exercise), (2) closed-hand position, (3) dynamic bipedal squat, (4) static unipedal squat, and (5) dynamic unipedal squat on the contralateral leg. All data were normalized as a percentage of maximal voluntary isometric contraction (MVIC).

RESULTS

A closed-hand position (exercise 2) instead of an open-hand position (exercise 1) resulted in lower MT (mean difference = 3.44% MVIC) and LT (mean difference = 7.76% MVIC) activity. Incorporating the lower limb (exercises 3-5) increased UT activity when compared with exercise 1 (mean differences = 3.67, 2.68, 5.02% MVIC, respectively), which in general resulted in increased UT : MT ratios. Additionally, LT activity decreased when a dynamic unipedal squat was added (mean difference: 4.90% MVIC). For the serratus anterior, the greatest activity occurred during elevation in a static unipedal squat position (exercise 4, 22.90% MVIC).

CONCLUSIONS

Incorporating the kinetic chain during shoulder-elevation exercises influenced scapular muscle activity and ratios. In particular, incorporating the lower limb resulted in more UT activity, whereas the open-hand position increased MT and LT activity.

Muscle Activity Ratios of Scapular Stabilizers During Closed Kinetic Chain Exercises in Healthy Shoulders: A Systematic Review

CONTEXT

Selective strengthening of scapular stabilizers is one of the emphases of the recent literature. Closed kinetic chain (CKC) exercises are used extensively in shoulder rehabilitation. However, a limited number of studies have reported scapular muscle ratios during CKC exercises.

OBJECTIVES

To determine the CKC exercises producing the optimal ratios of the scapular stabilizer muscles in healthy shoulders.

EVIDENCE ACQUISITION

A systematic search within PubMed, Embase, CINAHL Plus, and SPORTDiscus with Full Text and ULAKBIM National Medical Database was performed up to January 2018. Studies were selected according to the predetermined criteria. If the pooled mean ratios (upper trapezius [UT]/middle trapezius [MT], UT/lower trapezius [LT], and UT/serratus anterior [SA]), which were calculated from the percentage of maximum voluntary contractions of muscles, were <0.60, these exercises were considered as ideal for higher activation of the MT, LT, and SA than the UT.

EVIDENCE SYNTHESIS

The search identified 1284 studies, and 29 observational studies were included for review. Seventy-nine CKC exercises were determined. Four exercises for the MT, 9 for the LT, and 59 for the SA were identified from the articles as being optimal exercises to activate the specified muscle more than the UT.

CONCLUSIONS

This review identified optimal CKC exercises that provide good ratios between the MT, LT, and SA with the UT. Most exercises have optimal UT/SA ratios, but some exercises performed on unstable surfaces may lead to excessive activation of the UT relative to the SA. For the UT/MT, the isometric low row, inferior glide, and half supine pull-up with slings are the ideal exercises. Isometric one-hand knee push-up variations seem to be the best choice for the UT/LT. The results suggest that many CKC exercises may be utilized to enhance scapular muscle balance when rehabilitating shoulder pathology.