Standing and sidelying external rotation exercises produce high activation of the deltoid and infraspinatus. Holding a towel roll under the arm at 30° shoulder abduction during these exercises may decrease deltoid activity and increase infraspinatus activity. The objective was to determine if the addition of a towel under the arm during standing and sidelying external rotation affects EMG activity of the infraspinatus, middle and posterior deltoid, and pectoralis major, compared to the no towel condition. 20 male volunteers (age; 26 ± 3, height; 1.80 m ± .07 m, weight; 77 kg ± 10 kg) had right dominant hand, bilaterally healthy shoulders with no current cervical pathology, and no skin infection or lesion of the shoulder. Maximal voluntary isometric contraction for the infraspinatus, middle and posterior deltoid, and pectoralis major and external rotation in standing and sidelying with and without a towel roll were performed. Normalized average and peak EMG amplitude was compared between the towel conditions during standing and sidelying external rotation. Both infraspinatus and pectoralis major activity had no significant differences between the towel conditions in standing and sidelying (P > .05). In standing and sidelying, posterior deltoid activity was significantly greater with a towel roll (.008 ≤ P ≤ .035 and .008 ≤ P ≤ .018, respectively). Middle deltoid activity had no significant differences between the towel conditions in standing (P > .05). However, in sidelying, middle deltoid activity was significantly lower with a towel roll (.011 ≤ P ≤ .000). The only muscle activation change during standing external rotation with the application of a towel roll was an increase of the posterior deltoid. During sidelying external rotation, holding a towel roll decreased middle deltoid activity and increased posterior deltoid activity. Thus, this study indicates that holding a towel roll under the arm during standing external rotation exercise does not appear to produce desired effects on muscle activation. However, application of a towel roll under the arm could be recommended during sidelying external rotation exercise in order to possibly reduce the superior glide of the humerus, due to decrease muscle activation of the middle deltoid.

Progressive overload through the range of motion (ROM) is important for proper rehabilitation of muscle strength, yet varies across types of resistance for a given exercise. The purpose of this study was to compare strength curves (SC) for shoulder internal (IR) and external rotation (ER) with resistance curves (RC) for two application angles (A and B) of Thera-Band® resistance to determine which application angle best overloads IR and ER through the ROM. Thirty volunteer subjects participated in this study. SCs were obtained experimentally by measuring maximal isometric torque for IR and ER from 30° to 135°. RCs were calculated using regression equations from the literature. Significant differences (p < 0.05) were found between the SCs and RCs for both application angles during IR and ER. The findings of this study indicate that application angles A and B do not provide optimal loading when performing shoulder IR and ER exercises.

Abstract Isolated lateral malleolar supination-external rotation (SER) -type ankle fractures without incongruity on the standard radiographs can be either stable or unstable depending on the status of the deep deltoid ligament. Neither clinical signs of injury on the medial aspect of the ankle nor the displacement of fibular fracture on mortise radiographs seem to predict stability. Therefore, stress testing has been adopted in clinical use. No “gold standard” method exists but the manual external rotation (ER) stress test is the most extensively studied. The ER stress test has some disadvantages, and other methods—such as gravity stress radiography and magnetic resonance imaging—have been suggested instead. However, the evidence to support the use of these methods is still insufficient. The aims of this dissertation were to assess the roles of (1) morphological factors from standard radiographs of 286 patients, (2) clinical findings on the medial side of the ankle and gravity stress radiography of 79 patients, and (3) MRI of 61 patients in evaluating the stability of the ankle mortise in patients with unimalleolar SER-type fractures with no talar shift on standard radiographs. The ER stress test result was considered to be the reference for stability throughout these studies. We found that a fracture line width &lt; 2 mm in lateral radiographs, only two fracture fragments, and female sex are independent factors predicting a stable ankle mortise. Neither clinical signs on the medial side of the ankle nor gravity stress radiography alone predict the stability of the ankle mortise accurately. According to our MRI findings, total tears of the deep deltoid ligaments are rare, and partial tears are common in this this patient group. The reliability of the MRI assessment is only moderate. In conclusion, patients with non-comminuted fractures and &lt; 2 mm displacement on lateral radiographs have stable ankle mortises and need no further stress testing. The gravity stress radiography is an accurate test for the evaluation of the ankle mortise stability only if the clinical signs indicate a similar result with the gravity stress radiographs. The use of MRI provides no additional benefit compared to ER stress testing for stability evaluation of an SER-type ankle fracture. / Tiivistelmä Supinaatio-ulkokiertomekanismilla syntyneet isoloidut ulkokehräsluun murtumat ilman röntgenkuvassa näkyvää telaluun siirtymää voivat olla joko vakaita tai epävakaita nilkan sisemmän nivelsiteen syvän lehden tilasta riippuen. Kliinisessä tutkimuksessa todettujen nilkan sisäreunan vamman merkkien tai röntgenkuvauksella todettavan ulkokehräsluun murtuman virheasennon ei ole osoitettu ennustavan nivelhaarukan mahdollista epävakautta, joten nilkkaa kuormittaen tehtäviä röntgenkuvauksia on otettu kliiniseen käyttöön. Mikään näistä kuvausmenetelmistä ei ole niin sanottu kultainen standardi, mutta ulkokiertovääntötestiä (ER-testi) on tutkittu laajimmin. ER-testin käyttöön liittyy kuitenkin ongelmia, joiden vuoksi niin sanottua painovoimakuvausta tai muun muassa magneettikuvausta (MRI) on ehdotettu käytettäväksi sen sijaan. Näiden menetelmien käyttöä tukeva tieteellinen näyttö on kuitenkin vielä riittämätöntä. Tämän väitöskirjatyön tarkoituksena oli tutkia (1) 286 potilaan tavallisista kuormittamattomista röntgenkuvista morfologisten tekijöiden, (2) 79 potilaan nilkan sisäreunan kliinisen tutkimuksen ja painovoimakuvauksen sekä (3) 61 potilaalla MRI:n merkitystä ja tarkkuutta arvioitaessa supinaatio-ulkokiertomekanismilla syntyneiden ulkokehräsluun murtumien vakautta. ER-testin tulosta käytettiin referenssinä nivelhaarukan vakaudelle kaikissa osatöissä. Sivukuvasta mitattuna ulkokehräsluun murtuman leveys &lt; 2 mm, vain kahden kappaleen murtuma ja naissukupuoli ovat itsenäisiä vakaata nivelhaarukkaa ennustavia tekijöitä. Kliininen tutkimus tai painovoimakuvaus eivät yksinään pysty ennustamaan nivelhaarukan vakautta riittävän tarkasti. MRI:n perusteella sisemmän nivelsiteen syvän lehden täydelliset repeämät ovat tässä vammatyypissä harvinaisia mutta osittaiset repeämät ovat hyvin tavallisia huolimatta ER-testin tuloksesta. MRI:n tulkinnan luotettavuus on ainoastaan kohtalainen. Yhteenvetona voidaan todeta, että ilman ilmeistä telaluun siirtymää röntgenkuvassa yksinkertaiset supinaatio-ulkokiertomekanismilla syntyneet ulkokehräsluun murtumat ovat vakaita eikä nivelhaarukan vakauden testaaminen ole tarpeen, jos murtumaraon leveys sivukuvassa on &lt; 2 mm. Painovoimakuvaus on luotettava, mikäli sen tulos on sama ulkoisten vamman merkkien kanssa. Magneettikuvauksesta ei ole hyötyä arvioitaessa tämän nilkkamurtumatyypin vakautta.