Comparison of scapular position and upper extremity muscle strength in patients with and without lateral epicondylalgia: a case-control study

Lateral Epicondylalgia and Thoracic Kyphosis: A Study on Young Athletes

OBJECTIVE

The etiology of lateral epicondylalgia (LE) remains unclear, although it has been linked to various factors. Recent theories suggest a potential connection between LE and impairments in the kinetic chain. In our study, we aimed to investigate the association between another factor influencing kinetic chain impairment, specifically an increased angle of thoracic kyphosis, and the presence of initial signs of LE in young athletes.

DESIGN

This study employed an observational, case-control design.

SETTING

The participants underwent examination during a routine preventive checkup conducted by a sports physician at Novi Sad Healthcare Center, Sports Medicine Center.

PARTICIPANTS

One hundred young athletes aged 10 to 15 years were included in the study. Half of the participants reported pain in the lateral aspect of the elbow during maximal hand grip, while the remaining athletes served as controls and did not experience any pain.

ASSESSMENT OF INDEPENDENT VARIABLES

Thoracic kyphosis inclination angles were measured using a digital inclinometer.

MAIN OUTCOME MEASURES

Pain was assessed using the pressure pain threshold at a specific point associated with lateral epicondylalgia, measured by a digital algometer.

RESULTS

Participants exhibiting initial signs of LE displayed significantly different angles of anteroposterior curvatures of the spine compared with the control group. Moreover, the angle of thoracic kyphosis was significantly associated with pain in the lateral aspect of the elbow.

CONCLUSIONS

Our findings confirm an association between initial signs of lateral epicondylalgia and the grade of thoracic kyphosis in young athletes.

Deficits in neuromuscular control of increasing force in patients with chronic lateral epicondylitis

Objective: This study investigated the neuromuscular control of increasing and releasing force in patients with chronic lateral epicondylitis (CLE). Methods: Fifteen patients with CLE (10 males, 5 females, 46.5 ± 6.3 years) and fifteen healthy participants (9 males, 6 females, 45.3 ± 2.5 years) participated in this study. In addition to power grip and maximal voluntary contraction (MVC) of wrist extension, force fluctuation dynamics and characteristics of inter-spike intervals (ISI) of motor units (MUs) with various recruitment thresholds in the extensor carpi radialis brevis (ECRB) and extensor carpi radialis longus (ECRL) during a designated force-tracking task with a trapezoidal target (0%-75%-0% MVC) were assessed. Results: Besides a smaller MVC of wrist extension, the patients exhibited significantly greater task errors (p = 0.007) and force fluctuations (p = 0.001) during force increment than the healthy counterparts. Nevertheless, no force variables significantly differed between groups during force release (p > 0.05). During force increment, the amplitudes of the motor unit action potential of the ECRB and ECRL muscles of the patients were smaller than those of the heathy counterparts (p < 0.001). The patient group also exhibited a higher percentage of motor units (MU) with lower recruitment threshold (<5% MVC) in the ECRL/ECRB muscles and a lower percentage of MU with higher recruitment threshold (>40% MVC) in the ECRB muscle, compared to the healthy group. During force increment, the patient group exhibited a higher rate of decrease in inter-spike intervals (ISIs) of motor units with lower recruitment thresholds (<10% MVC) in the ECRB and ECRL muscles, compared to the control group (p < 0.005). Conclusion: The patients with CLE exhibited more pronounced impairment in increasing force than in releasing force. This impairment in increasing force is attributed to deficits in tendon structure and degenerative changes in the larger motor units of the wrist extensors. To compensate for the neuromuscular deficits, the rate of progressive increase in discharge rate of the remaining smaller motor units (MUs) is enhanced to generate force. Significance: The deficits in neuromuscular control observed in CLE with degenerative changes cannot be fully explained by the experimental pain model, which predicts pain-related inhibition on low-threshold motor units.

The Management of Valgus Extension Overload Syndrome Experienced with Hitting in a High School Baseball Player: A Case Report

Background

Valgus extension overload syndrome (VEOS) of the elbow is a condition associated with overhead athletes. However, the non-surgical management of these individuals is not well documented.

Purpose

To discuss the unique presentation, management, and outcomes of an adolescent baseball player with a chronic history of VEOS experienced during hitting.

Case Description

A 15-year-old right-handed high school baseball catcher presented with a six-month history of right-sided ulnar elbow pain. Elbow MRI w/ contrast was consistent with VEOS. The initial examination demonstrated excessive resting right-sided humeral external rotation compared to his left. Valgus stress testing in the subject's hitting position reproduced symptoms, which were alleviated with retest while correcting excessive humeral external rotation. Weakness of the humeral internal rotators and stiffness/shortness of the posterior shoulder were found and thought to relate to the humeral contribution to his elbow movement dysfunction. Rehabilitation emphasized addressing impairments contributing to excessive humeral external rotation with reintegration into batting.

Outcomes

After five weeks of physical therapy, the subject returned to soft toss hitting at approximately 75% velocity for the first time since symptom onset, without pain. At seven months after discharge, a phone conversation confirmed that the subject had returned to baseball without limitations.

Discussion

Despite the concept of 'regional interdependence', common proximal impairments are often assumed to contribute to elbow pain without a clear biomechanical rationale. Future research demonstrating the specific biomechanical effects of the shoulder on the elbow is needed, in addition to more accessible examination strategies to assess their relationship.

Level of Evidence

5.

An Investigation of Maximal Strength of the Upper Limb Bilaterally in Individuals With Lateral Elbow Tendinopathy: A Systematic Review With Meta-Analysis

OBJECTIVE

The aim of this study was to investigate whether there is evidence of bilateral upper limb strength deficits in individuals with unilateral lateral elbow tendinopathy (LET).

METHODS

The electronic databases Medline via Ovid, PubMed, and Scopus were searched from inception to March 2020. Included studies encompassed maximal strength outcomes of any upper limb and appendicular musculature in individuals with LET and an asymptomatic comparator. Study quality was rated using a modified version of the Epidemiological Appraisal Instrument. Hedges g effect sizes (ES) and 95% CIs were calculated for comparisons of maximal strength in the LET group and an asymptomatic control group. Meta-analysis using a random-effects model was performed when possible.

RESULTS

Fourteen studies were included. Quality appraisal resulted in a mean Epidemiological Appraisal Instrument score of 46% (SD = 10%). Meta-analysis revealed strength deficits in shoulder abduction (pooled ES = -0.37 [95% CI = -0.62 to -0.12]) and shoulder external rotation (pooled ES = -0.55 [95% CI = -0.83 to -0.28]) of the symptomatic limb compared with an asymptomatic control group. Meta-analysis also revealed maximal strength deficits in the upper trapezius (pooled ES = -0.26 [95% CI = -0.49 to -0.02]) of the asymptomatic limb compared with an asymptomatic control group. There was also consistent evidence for strength deficits in the serratus anterior, lower trapezius, and wrist extensor muscles and deficits in grip strength of the symptomatic limb as well as strength deficits in the wrist extensor muscles of the asymptomatic limb in individuals with unilateral LET.

CONCLUSION

In individuals with LET, there were maximal strength deficits in shoulder abduction, shoulder external rotation, serratus anterior and lower trapezius muscles, and wrist extension, as well as deficits in grip strength of the symptomatic limb compared with an asymptomatic control group. In addition, there appeared to be strength deficits in the upper trapezius muscle, wrist extension, and metacarpophalangeal joint flexion and extension, as well as deficits in grip strength of the asymptomatic limb in individuals with LET compared with an asymptomatic control group. These results suggest bilateral strength deficits.

IMPACT

These findings highlight the importance of a thorough physical examination and appropriate strengthening intervention for the upper limb with a focus on shoulder and scapular stabilizers, in addition to forearm muscles, in individuals with LET.

LAY SUMMARY

In people with tennis elbow, widespread strength deficits, including weakness of the shoulder, forearm, and wrist muscles, may exist. Interestingly, some of these weaknesses appear on both the affected and the unaffected sides in people with tennis elbow. A physical therapist can help strengthen these areas.

The analgesic effect of joint mobilization and manipulation in tendinopathy: a narrative review

Objective: To summarize the available literature with regards to the potential analgesic effect and mechanism of joint mobilization and manipulation in tendinopathy. Results: The effect of these techniques in rotator cuff tendinopathy and lateral elbow tendinopathy, applied alone, compared to a placebo intervention or along with other interventions has been reported in some randomized controlled trials which have been scrutinized in systematic reviews. Due to the small randomized controlled trials and other methodological limitations of the evidence base, including short-term follow-ups, small sample size and lack of homogenous samples further studies are needed. Literature in other tendinopathies such as medial elbow tendinopathy, de Quervain's disease and Achilles tendinopathy is limited since the analgesic effect of these techniques has been identified in few case series and reports. Therefore, the low methodological quality renders caution in the generalization of findings in clinical practice. Studies on the analgesic mechanism of these techniques highlight the activation of the descending inhibitory pain mechanism and sympathoexcitation although this area needs further investigation. Conclusion: Study suggests that joint mobilization and manipulation may be a potential contributor in the management of tendinopathy as a pre-conditioning process prior to formal exercise loading rehabilitation or other proven effective treatment approaches.

The Effect of Scapular Muscle Strengthening on Functional Recovery in Patients With Lateral Elbow Tendinopathy: A Pilot Randomized Controlled Trial

CONTEXT

There is a lack of consensus on the best management approach for lateral elbow tendinopathy (LET). Recently, scapular stabilizer strength impairments have been found in individuals with LET.

OBJECTIVE

The purpose of this study was to compare the effectiveness of local therapy (LT) treatment to LT treatment plus a scapular muscle-strengthening (LT + SMS) program in patients diagnosed with LET.

DESIGN

Prospective randomized clinical trial.

SETTING

Multisite outpatient physical therapy.

PATIENTS

Thirty-two individuals with LET who met the criteria were randomized to LT or LT + SMS.

INTERVENTIONS

Both groups received education, a nonarticulating forearm orthosis, therapeutic exercise, manual therapy, and thermal modalities as needed. Additionally, the LT + SMS group received SMS exercises.

MAIN OUTCOME MEASURE

The primary outcome measure was the patient-rated tennis elbow evaluation; secondary outcomes included global rating of change (GROC), grip strength, and periscapular muscle strength. Outcomes were reassessed at discharge, 6, and 12 months from discharge. Linear mixed-effect models were used to analyze the differences between groups over time for each outcome measure.

RESULTS

The average duration of symptoms was 10.2 (16.1) months, and the average total number of visits was 8.0 (2.2) for both groups. There were no significant differences in gender, age, average visits, weight, or height between groups at baseline (P > .05). No statistical between-group differences were found for any of the outcome measures. There were significant within-group improvements in all outcome measures from baseline to all follow-up points (P < .05).

CONCLUSION

The results of this pilot study suggest that both treatment approaches were equally effective in reducing pain, improving function, and increasing grip strength at discharge as well as the 6- and 12-month follow-ups. Our multimodal treatment programs were effective at reducing pain and improving function up to 1 year after treatment in a general population of individuals with LET.