Kyle Matsel, Claire Davies and Tim Uhl
Clinical Scenario: Shoulder pain is a very common symptom encountered in outpatient physical therapy practice. In addition to therapeutic exercise and manual therapy interventions, trigger point dry needling (TDN) has emerged as a possible treatment option for reducing shoulder pain and improving function. Dry needling consists of inserting a thin stainless-steel filament into a myofascial trigger point with the intention of eliciting a local twitch response of the muscle. It is theorized that this twitch response results in reduced muscle tension and can aid in reduced pain and disability. To this point, multiple studies have found TDN to be effective at reducing pain and improving function in the short-term, but the long-term outcomes remain unknown. Clinical Question: Does the addition of TDN to an exercise program result in better long-term pain intensity and disability reduction in patients with shoulder pain? Summary of Findings: Improvement in long-term pain and function can be expected regardless of the addition of TDN to an evidence-based exercise program for patients with shoulder pain. Clinical Bottom Line: Either TDN or an evidence-based therapeutic exercise program elicits improved long-term pain and disability reduction in patients with shoulder pain, which suggests that clinicians can confidently use either approach with their patients. Strength of Recommendation: Strong evidence (level 2 evidence with PEDro scores >8/10) suggesting that TDN does not outperform therapeutic exercise regarding long-term pain reduction.
Barbara Baker, Eric Koch, Kevin Vicari and Kyle Walenta
Introduction: Sports-related concussions (SRCs) have received attention due to their prevalence in youth. An SRC results from a strong force causing neurological impairment. Recent research has recommended rehabilitation within the first week post-SRC after 24 to 48 hours of rest. The postacute phase is defined as 48 hours to 7 days post-SRC. It is imperative to evaluate the most effective mode and intensity of physical activity to reduce symptoms and improve outcomes. Methods: CINAHL, PubMed, SPORTDiscus, and Web of Science databases were used to search the terms “brain concussion” AND “exercise” and variations of these terms. The evidence level for each study was evaluated using the 2011 Oxford Center for Evidence-Based Medicine Guide. The methodological rigor of each study was evaluated using a scale adapted from Medlicott and Harris. Results: Two thousand sixty-eight records were identified. Six studies were included in this systematic review. Three studies were classified as moderately strong. The remaining 3 studies were considered weak. Five of the studies used either a cycle ergometer or a treadmill. The sixth study used walking, cycling, and swimming, as well as sports drills. All of these modes of exercise were determined to be safe. All studies utilized low- and moderate-intensity interventions, which were found to be nondetrimental and showed improved recovery time and symptom resolution. Five of the studies also incorporated components of high-intensity exercise that was also found to be nondetrimental, and they showed a positive influence on recovery time and symptom resolution. However, all activity in each of the reviewed studies started at a low level and progressed up to a higher level only as each individual client’s symptoms permitted. Discussion: Overall, this review found that various modes of activity at light-, moderate-, and high-intensity levels are efficacious and can be safely used during the postacute phase of SRC. Conclusion: Though the volume of literature at this time is limited, therapists should consider prescribing closely monitored individualized exercise programs utilizing progressive intensities when treating patients during the postacute phase of SRC.
Matthew D. Watson, George J. Davies and Bryan L. Riemann
Context: A recent report demonstrated moderate to strong relationships between seated single-arm shot-put (SSASP) test performance and isokinetic pushing forces at varying velocities, directly supporting the SSASP test as a reflection of multijoint upper-extremity strength. Yet, no previous work appears to have assessed whether the SSASP test is more reflective of shoulder flexion or elbow extension strength. Objective: To examine the relationship between isokinetic shoulder flexion and elbow extension strength and SSASP test performance and to compare limb symmetry indices (LSI) between the 2 tests. Design: Correlational design. Setting: Biomechanics laboratory. Patients (or Other Participants): A total of 30 healthy and physically active young adults. Intervention(s): Participants completed the SSASP test and concentric isokinetic (60°/s and 180°/s) shoulder flexion and elbow extension using their dominant and nondominant arms. Main Outcome Measures: SSASP test performance and isokinetic shoulder flexion and elbow extension peak torques as well as LSI between the 2 tests. Results: Strong relationships were observed between SSASP ranges and isokinetic peak torques at each velocity for both shoulder and elbow (r ≥ .804, P < .001). While the Bland–Altman results on the LSI only demonstrated a significant bias for the shoulder (60°/s, P = .009), limits of agreement results demonstrated extremely wide intervals (32.5%–52.1%). Conclusions: The SSASP test is a multijoint upper-extremity functional performance test that is reflective of equal shoulder flexion and elbow extension contributions; however, there was large variability regarding the agreement between the SSASP LSI and isokinetic shoulder and elbow strength LSI.
Xiaoyue Hu, Jingxian Li and Lin Wang
Twenty-four healthy adults, including 12 females and 12 males, participated in the study. Each female participant completed three trials in three different phases of one menstrual cycle, which included follicular, ovulatory, and luteal phases. The study aimed to investigate whether there is any difference in joint kinetic sense, neuromuscular coordination, and isokinetic muscle strength (a) between healthy males and females at different phases of the menstrual cycle and (b) between females at different phases of the menstrual cycle. The outcome measures included the number of jumps in the square-hop test and ankle and knee proprioception, which were assessed by an electric-driven movable frame rotated at 0.4 deg/s and isokinetic muscle strength measured by a computerized dynamometer (Biodex). For the square-hop test (p = .006), ankle dorsiflexion/plantar flexion (p < .05), knee flexion/extension (p < .05), the relative peak torque of the isokinetic muscle strength at the 60° and 180° knee flexion/extension (p < .001), and the 30° and 120° ankle plantar flexion/dorsiflexion (p < .05) between females and males showed significant differences. For the females at different phases of the menstrual cycle, significant differences were found on ankle dorsiflexion (p = .003), plantar flexion (p = .023), knee extension (p = .029), the square-hop test (p = .036), and relative peak torque of isokinetic muscle strength at 180° knee flexion (p = .029). This study demonstrated that there are sex differences in lower limb proprioception and mechanical function. Females at ovulatory and luteal phases have better lower limb proprioception than at the follicular phase.
David C. Kingston and Stacey M. Acker
A musculoskeletal model of the right lower limb was developed to estimate 3D tibial contact forces in high knee flexion postures. This model determined the effect of intersegmental contact between thigh–calf and heel–gluteal structures on tibial contact forces. This model includes direct tracking and 3D orientation of intersegmental contact force, femoral translations from in vivo studies, wrapping of knee extensor musculature, and a novel optimization constraint for multielement muscle groups. Model verification consisted of calculating the error between estimated tibial compressive forces and direct measurements from the Grand Knee Challenge during movements to ∼120° of knee flexion as no high knee flexion data are available. Tibial compression estimates strongly fit implant data during walking (R 2 = .83) and squatting (R 2 = .93) with a root mean squared difference of .47 and .16 body weight, respectively. Incorporating intersegmental contact significantly reduced model estimates of peak tibial anterior–posterior shear and increased peak medial–lateral shear during the static phase of high knee flexion movements by an average of .33 and .07 body weight, respectively. This model supports prior work in that intersegmental contact is a critical parameter when estimating tibial contact forces in high knee flexion movements across a range of culturally and occupationally relevant postures.
Anna Lee, Tanvi Bhatt, Xuan Liu, Yiru Wang, Shuaijie Wang and Yi-Chung (Clive) Pai
The purpose was to examine and compare the longer-term generalization between 2 different practice dosages for a single-session treadmill slip-perturbation training when reexposed to an overground slip 6 months later. A total of 45 older adults were conveniently assigned to either 24 or 40 slip-like treadmill perturbation trials or a third control group. Overground slips were given immediately after initial training, and at 6 months after initial training in order to examine immediate and longer-term effects. The performance (center of mass stability and vertical limb support) and fall percentage from the laboratory-induced overground slips (at initial posttraining and at 6 mo) were measured and compared between groups. Both treadmill slip-perturbation groups showed immediate generalization at the initial posttraining test and longer-term generalization at the 6-month retest. The higher-practice-dosage group performed significantly better than the control group (P < .05), with no difference between the lower-practice-dosage and the control groups at the 6-month retest (P > .05). A single session of treadmill slip-perturbation training showed a positive effect for reducing older adults’ fall risk for laboratory-induced overground slips. A higher-practice dosage of treadmill slip perturbations could be more beneficial for further reducing fall risk.
Seong-won Han, Andrew Sawatsky, Azim Jinha and Walter Herzog
Vastus medialis (VM) weakness is thought to alter patellar tracking, thereby changing the loading of the patellofemoral joint (PFJ), resulting in patellofemoral pain. However, it is challenging to measure VM force and weakness in human studies, nor is it possible to measure the associated mechanical changes in the PFJ. To obtain fundamental insight into VM weakness and its effects on PFJ mechanics, the authors determined PFJ loading in the presence of experimentally simulated VM weakness. Skeletally mature New Zealand White rabbits were used (n = 6), and the vastus lateralis, VM, and rectus femoris were stimulated individually through 3 custom-built nerve cuff electrodes. Muscle torque and PFJ pressure distribution were measured while activating all muscles simultaneously, or when the vastus lateralis and rectus femoris were activated, while VM was not, to simulate a quadriceps muscle strength imbalance. For a given muscular joint torque, peak pressures were greater and joint contact areas were smaller when simulating VM weakness compared with the condition where all muscles were activated simultaneously. The results in the rabbit model support that VM weakness results in altered PFJ loading, which may cause patellofemoral pain, often associated with a strength imbalance of the knee extensor muscle group.
Masahiro Yamada and Louisa D. Raisbeck
Contexts: Directing an individual’s attention to the effect of the movements (external focus) has been shown to improve performance than directing attention to body movements (internal focus). However, the effect of attentional focus instructions specific to movement quality has not been investigated thoroughly. Objective: To compare the effects of internal and external focus instructions specific to body movements. Design: Mixed design, 2 (sex) × 2 (instructions). Settings: Laboratory setting. Participants: A total of 40 participants (males, n = 20; mean [SD]; age = 22.0 [2.19] y; height = 179.33 [5.90] cm; mass = 77.7 [13.04] kg; females, n = 20; age = 22.0 [3.87] y; height = 164.84 [5.80] cm; mass = 71.48 [20.66] kg) were recruited. Intervention: Participants completed 2 consecutive jumps (ie, a forward jump from a height and then a maximal vertical jump) with internal focus and external focus instructions. External focus was elicited by placing pieces of tape on the participants’ legs. Main Outcome measures: Landing quality was measured by the Landing Error Scoring System to assess movement quality, and the vertical jump height was measured by Vertec. Results: The performance results showed that the external focus condition resulted in superior vertical jump height compared with the internal focus condition (P < .05). Although landing quality did not show significant differences between 2 conditions, the effect size (η 2 = .09) indicated that landing quality was better when participants adopted an external, rather than an internal focus of attention (P = .07). Conclusions: The body-oriented instructions can be provided externally by adding artificial external cues and directing attention to them. Importantly, the findings were evident in a qualitative assessment that can be adopted by practitioners. The results suggest that practitioners should adopt an external focus cue for performance and also consider using an external focus for movement quality.