Context: The single-leg squat task is often used as a rehabilitative exercise or as a screening tool for the functional movement of the lower limb. Objective: To establish the effect of 3 different positions of the nonstance leg on 3-dimensional kinematics, muscle activity, and center of mass displacement during a single-leg squat. Design: Within-subjects, repeated-measures design. Setting: Movement analysis laboratory. Participants: A total of 10 participants, aged 28.2 (4.42) years performed 3 squats to 60° of knee flexion with the nonstance (1) hip at 90° flexion and knee at 90° flexion, (2) hip at 30° flexion with the knee fully extended, or (3) hip in neutral/0° and the knee flexed to 90°. Main Outcome Measures: Trunk, hip, knee and ankle joint angles, and center of mass displacement were recorded with inertial sensors while muscle activity was captured through wireless electromyography. Results: Most trunk flexion (21.38° [18.43°]) occurred with the nonstance hip at 90° and most flexion of the stance hip (23.10° [6.60°]) occurred with the nonstance hip at 0°. Biceps femoris activity in the 90° squat was 40% more than in the 0° squat, whereas rectus femoris activity in the 0° squat was 29% more than in the 90° squat. Conclusion: The position of the nonstance limb should be standardized when the single-leg squat is used for assessment and be adapted to the aim when used in rehabilitation.
Benita Olivier, Samantha-Lynn Quinn, Natalie Benjamin, Andrew Craig Green, Jessica Chiu and Weijie Wang
Erik A. Wikstrom, Sajad Bagherian, Nicole B. Cordero and Kyeongtak Song
Clinical Scenario: Chronic ankle instability (CAI) is a complex musculoskeletal condition that results in sensorimotor and mechanical alterations. Manual therapies, such as ankle joint mobilizations, are known to improve clinician-oriented outcomes like dorsiflexion range of motion, but their impact on patient-reported outcomes remains less clear. Focused Clinical Question: Do anterior-to-posterior ankle joint mobilizations improve patient-reported outcomes in patients with chronic ankle instability? Summary of Key Findings: Three studies (2 randomized controlled trials and 1 prospective cohort) quantified the effect of at least 2 weeks of anterior-to-posterior ankle joint mobilizations on improving patient-reported outcomes immediately after the intervention and at a follow-up assessment. All 3 studies demonstrated significant improvements in at least 1 patient-reported outcome immediately after the intervention and at the follow-up assessment. Clinical Bottom Line: At least 2 weeks of ankle joint mobilization improves patient-reported outcomes in patients with chronic ankle instability, and these benefits are retained for at least a week following the termination of the intervention. Strength of Recommendation: Strength of recommendation is grade A due to consistent good-quality patient-oriented evidence.
Natalia Romero-Franco, Juan Antonio Montaño-Munuera, Juan Carlos Fernández-Domínguez and Pedro Jiménez-Reyes
Context: New methods are being validated to easily evaluate the knee joint position sense (JPS) due to its role in the sports movement and the risk of injury. However, no studies to date have considered the open kinetic chain (OKC) technique, despite the biomechanical differences compared with closed kinetic chain movements. Objective: To analyze the validity and reliability of a digital inclinometer to measure the knee JPS in the OKC movement. Design: The validity and intertester and intratester reliability of a digital inclinometer for measuring knee JPS were evaluated. Setting: Sports research laboratory. Participants: A total of 18 athletes (11 males and 7 females; 28.4 [6.6] y; 71.9 [14.0] kg; 1.77 [0.09] m; 22.8 [3.2] kg/m2) voluntary participated in this study. Main Outcomes Measures: Absolute angular error (AAE), relative angular error (RAE), and variable angular error (VAE) of knee JPS in an OKC. Results: Intraclass correlation coefficient (ICC) and standard error of the mean (SEM) were calculated to determine the validity and reliability of the inclinometer. Data showed excellent validity of the inclinometer to obtain proprioceptive errors compared with the video analysis in JPS tasks (AAE: ICC = .981, SEM = 0.08; RAE: ICC = .974, SEM = 0.12; VAE: ICC = .973, SEM = 0.07). Intertester reliability was also excellent for all the proprioceptive errors (AAE: ICC = .967, SEM = 0.04; RAE: ICC = .974, SEM = 0.03; VAE: ICC = .939, SEM = 0.08). Similar results were obtained for intratester reliability (AAE: ICC = .861, SEM = 0.1; RAE: ICC = .894, SEM = 0.1; VAE: ICC = .700, SEM = 0.2). Conclusions: The digital inclinometer is a valid and reliable method to assess the knee JPS in OKC. Sport professionals may evaluate the knee JPS to monitor its deterioration during training or improvements throughout the rehabilitation process.
Carl G. Mattacola
Takashi Abe, Jeremy P. Loenneke, Robert S. Thiebaud and Mark Loftin
Context: Studies developed the frail elderly handgrip strength (HGS) diagnostic criteria using multiple types of handgrip dynamometers. If different handgrip dynamometers report different values, then this would have the potential to misclassify people into the wrong diagnostic category. Objective: To examine the characteristics of HGS measured by 2 standard handgrip dynamometers and to investigate the influence of hand size on HGS. Setting: University research laboratory. Participants: A total of 87 young and middle-aged adults between the ages of 20 and 60 years participated in this study. Main Outcome Measures: Standard methods of HGS measurements were used for hydraulic and Smedley spring-type dynamometers, although the participants were instructed to maintain an upright standing position in both tests. Results: Test–retest reliability of hydraulic and Smedley dynamometers provided comparable results to that observed with previous studies. However, the difference in HGS between the 2 dynamometers (Hydraulic–Smedley difference) was positively associated (r = .670, P < .001) with the mean of the 2 dynamometers. The participants who had relatively low HGS (at least <35 kg) produced similar HGS values when the 2 dynamometers were compared, whereas persons who had relatively higher HGS (at least >45 kg) produced greater strength values with the hydraulic compared with the Smedley. The hand and palm lengths were weakly correlated (r = .349 and r = .358, respectively, both Ps < .001) with the difference in HGS between the 2 dynamometers. Conclusions: Test–retest reliability of hydraulic and Smedley dynamometers provides comparable results to previous studies. However, the difference in HGS between the 2 dynamometers was positively associated with the mean of the 2 dynamometers. This Hydraulic–Smedley difference would not affect persons who have relatively low HGS (at least <35 kg), while when HGS is relatively high, the comparison between dynamometers should be done with caution.
Jun-Seok Kim, Moon-Hwan Kim, Duk-Hyun Ahn and Jae-Seop Oh
Context: A winged scapula (WS) is associated with faulty posture caused by weakness of the serratus anterior (SA), which mainly acts as a scapular stabilizer muscle. It is important to accurately assess and train the SA muscle with a focus on scapula stabilizers during musculoskeletal rehabilitation of individuals with a WS. Objective: The authors examined muscle activity in the SA and pectoralis major (PM), upper trapezius (UT), and anterior deltoid (AD) as well as shoulder protraction strength during isometric shoulder protraction in individuals with and without a WS. Design: Cross-sectional study. Setting: A clinical biomechanics laboratory. Participants: In total, 27 males with no shoulder, neck, or upper-extremity pain participated. Main Outcome Measures: Isometric shoulder protraction strength was collected and surface electromyography used to measure the activity of the SA, PM, UT, and AD muscles and selective SA activity ratio to other shoulder muscles. Results: Electromyography activity of the SA muscle and shoulder protraction strength were significantly lower in individuals with a WS compared with the non-WS group (P < .05). In contrast, PM muscle activity and the PM-to-SA, UT-to-SA, and AD-to-SA ratios were significantly greater in individuals with a WS than in individuals without winging (P < .05). Conclusions: Isometric shoulder protraction for measuring SA strength in individuals with a WS should focus on isolated muscle activity of the SA, and SA strengthening exercises are important for individuals with a WS.
Fahimeh Kamali, Ehsan Sinaei and Maryam Morovati
Context: Chronic musculoskeletal disorders in the shoulder joint are often associated with myofascial trigger points (MTrPs), particularly in the upper trapezius (UT) muscle. Dry needling (DN) is a treatment of choice for myofascial pain syndrome. However, local lesions and severe postneedle soreness sometimes hamper the direct application of DN in the UT. Therefore, finding an alternative point of treatment seems useful in this regard. Objective: To compare the efficacy of UT versus infraspinatus (ISP) DN on pain and disability of subjects with shoulder pain. The authors hypothesized that ISP DN could be as effective as the direct application of DN in UT MTrP. Design: Single-blind randomized clinical trial. Setting: Sports medicine physical therapy clinic. Participants: A total of 40 overhead athletes (age = 36  y; 20 females and 20 males) with unilateral shoulder impingement syndrome were randomly assigned to the UT DN (n = 21) and ISP DN (n = 19) groups. Intervention: An acupuncture needle was directly inserted into the trigger point of UT muscle in the UT DN group and of ISP muscle in the ISP DN group. DN was applied in 3 sessions (2-day interval between each sessions) for each group. Main Outcome Measures: Pain intensity (visual analog scale), pain pressure threshold, and disability in the arm, shoulder, and hand were assessed before and after the interventions. Results: Pain and disability decreased significantly in both groups (P < .001) and pain pressure threshold increased significantly only in the ISP group (P = .02). However, none of the outcome measures showed a significant intergroup difference after treatments (P > .05). Conclusions: Application of DN for active MTrPs in the ISP can be as effective as direct DN of active MTrPs in the UT in improving pain and disability in athletes with shoulder pain, and may be preferred due to greater patient comfort in comparison with direct UT needling.
Il-young Yu, Dong-kyu Lee, Myoung-Joo Kang and Jae-seop Oh
Context: The infraspinatus muscle plays a particularly important role in producing primary external rotation (ER) torque and dynamic stability of the shoulder joint. Previous studies have reported that prone external rotation with horizontal abduction (PER), side-lying wiper exercise (SWE), and standing external rotation (STER) were effective exercises for strengthening the infraspinatus. However, we do not have enough knowledge about changes in muscle strength and dynamic muscle activity in each exercise under dynamic conditions. Objective: To compare the ER muscle strength, muscle activity among exercise methods and between muscle contraction types during 3 different exercises. Design: Repeated measures design in which ER muscle strength and muscle activities data were collected from subjects under 3 exercise conditions. Setting: Outpatient clinic. Participants: A total of 15 healthy men with no shoulder, neck, or upper-extremity pain were participated. Intervention: The subjects performed 3 different exercises randomly in concentric and eccentric using a Biodex dynamometer at an angular velocity of 60°/s. Main Outcome Measures: The ER peak torque (PT) data was collected and surface electromyography was used to measure the activity of the infraspinatus and posterior deltoid muscles and infraspinatus to posterior deltoid muscle activity ratio. Results: There was significant main effect for muscle contraction type in ER PT (P < .05). The concentric PT was greater during PER (P < .05) and SWE (P < .05) compared with eccentric. The main effect for exercise was found in ER PT and muscle activity (P < .05). The ER PT and infraspinatus muscle activity were the largest increased during PER whereas the lowest during STER in both concentric and eccentric (P < .05). Conclusion: The results of this study suggest that PER is an exercise for strengthening the infraspinatus muscle effectively.
Damla Gulpinar, Sibel Tekeli Ozer and Sevgi Sevi Yesilyaprak
Context: Alterations in posture and motion patterns are thought to play a role in developing shoulder injuries in overhead athletes. Taping is widely used in the sporting population, but there are limited empirical data regarding its effectiveness. Objectives: To determine and compare the effects of rigid and kinesio taping on shoulder rotation motions, posterior shoulder tightness (PST), and posture in overhead athletes. Design: Randomized controlled trial. Setting: Athletic training rooms. Participants: Eighty-six asymptomatic elite overhead athletes. Interventions: Participants were randomly divided into 4 groups: rigid taping group (RTG) that underwent therapeutic rigid taping, kinesio taping group (KTG) that underwent therapeutic kinesio taping, placebo group that underwent placebo kinesio taping (shoulder and scapular region taping for taping groups), and control group (no taping). Main Outcome Measures: Shoulder rotation motions, PST, and head and shoulder posture were evaluated at baseline, immediately after application and 60 to 72 hours after application for all groups. Results: Glenohumeral internal rotation increased immediately (P < .001) and at 60 to 72 hours after application in the KTG (P = .01), whereas it decreased immediately after application in the RTG (P < .001). Immediately after application, total rotation range of motion increased in the KTG (P =.02) and decreased in the RTG (P < .001), and there was a difference between groups (P = .02). Immediately after application, PST increased in the RTG (P < .001); after 60 to 72 hours, it decreased in the KTG (P = .04) and increased in the RTG (P = .01). Posture outcomes did not change significantly (P > .05). Conclusions: Kinesio taping may improve and rigid taping may worsen glenohumeral internal rotation and PST in overhead athletes. For increasing total rotation range of motion, kinesio taping is superior to rigid taping. Taping did not affect posture. Short-term kinesio taping in overhead athletes may be useful to improve glenohumeral internal rotation, total rotation range of motion, and PST.
Hio Teng Leong and Siu Ngor Fu
Context: Reduction of the subacromial space (SAS) during arm elevation may contribute to rotator cuff (RC) tendinopathy. The effects of scapular taping on the SAS in athletes with and without RC tendinopathy are unknown. Objective: To investigate the immediate effects of scapular taping on the SAS in athletes with and without RC tendinopathy. Design: Randomized controlled study with repeated measures. Setting: University laboratory. Participants: A total of 43 male volleyball players (17 asymptomatic and 26 with RC tendinopathy, mean age = 22.9 [3.5] y) participated in the study. Intervention: Three scapular taping protocols—no taping (control), taping with tension (therapeutic taping), and taping without tension (sham taping). Main Outcome Measures: Ultrasound measurements of the SAS with the arm at 0° and 60° of shoulder abduction, and the change in the SAS between 0° and 60° of shoulder abduction (SAS0°–60°) were calculated. Results: Athletes with RC tendinopathy demonstrated larger SAS with therapeutic taping at 60° of shoulder abduction (6.9 [1.9] mm vs 5.8 [1.7] mm, mean difference = 1.1 mm, 95% confidence interval, −1.80 to −0.39, P = .002) when compared with the no taping condition. The tendinopathy group also showed less reduction in the SAS with therapeutic taping during SAS0°–60° (2.0 [1.4] mm vs 2.8 [1.4] mm, P = .02) when compared with the no taping condition. When tape was applied to the scapula in asymptomatic athletes, our results showed a relatively small increase in the SAS with therapeutic taping during arm resting at 0° of abduction when compared with the no taping condition (8.7 [0.9] mm vs 8.3 [0.8] mm, mean difference = 0.4 mm, 95% confidence interval, −0.71 to −0.11, P = .01). Conclusions: Athletes with RC tendinopathy demonstrated less reduction of the SAS with rigid scapular taping during early arm abduction. Such observation was not evidenced in asymptomatic athletes.