Background: The aim of the study was to systematically evaluate the biceps femoris long head activation across cross-sectional hamstring strength exercise studies. Methods: A systematic review design was followed. The search strategy conducted in PubMed, Cochrane Library, and Web of Sciences databases found a total of 3643 studies. Once inclusion and exclusion criteria were applied, 29 studies were finally included in this systematic review. A total of 507 participants and 114 different exercises were analyzed. Exercises were evaluated individually and grouped into several categories: Nordics, isokinetic exercises, lunges, squats, deadlifts, good mornings, hip thrusts, bridges, leg curls, swings, hip and back extensions, and others. Results: Results showed the isokinetic and Nordic exercises as the categories with highest biceps femoris activation (>60% of Maximal Voluntary Isometric Contraction). Nordic hamstring exercise ankle dorsiflexion was the exercise that achieved the highest biceps femoris long head activation (128.1% of its Maximal Voluntary Isometric Contraction). Conclusions: The results from this systematic review suggest that isokinetic and Nordic exercises seem to be the best option to activate biceps femoris long head. Future studies evaluating the implementation of these exercises in prevention programs are needed.

Most of the studies evaluating core muscle activity during exercises have been conducted with healthy participants. The objective of this study was to compare core muscle activity and tolerability of a variety of dynamic and isometric exercises in patients with non-specific low back pain (NSLBP). 13 outpatients (average age 52 years; all with standing or walking work in their current or latest job) performed 3 consecutive repetitions at 15-repetition maximum during different exercises in random order. Surface electromyography was recorded for the rectus abdominis; external oblique and lumbar erector spinae. Patients rated tolerability of each exercise on a 5-point scale. The front plank with brace; front plank and modified curl-up can be considered the most effective exercises in activating the rectus abdominis; with a median normalized EMG (nEMG) value of 48% (34–61%), 46% (26–61%) and 50% (28–65%), respectively. The front plank with brace can be considered the most effective exercise in activating the external oblique; with a nEMG of 77% (60–97%). The squat and bird-dog exercises are especially effective in activing the lumbar erector spinae; with nEMG of 40% (24–87%) and 29% (27–46%), respectively. All the exercises were well tolerated; except for the lateral plank that was mostly non-tolerated. In conclusion; the present study provides a variety of dynamic and isometric exercises; where muscle activity values and tolerability can be used as guide to design evidence-based exercise programs for outpatients with NSCLBP.

Purpose. The aim of this study was to compare the pain severity, health-related quality of life (HRQoL), and risk of continue having pain with prognostic risk scores (PRS), between patients referring greater trochanteric pain syndrome (GTPS) and chronic low back pain (CLBP). Methods. A descriptive, cross-sectional design using nonprobability convenience sampling was performed. A total sample of 102 patients were recruited from two primary health-care centers and divided into GTPS (n = 51) and CLBP (n = 51) groups. The primary outcome was pain severity which was assessed with the Spanish version of the Graded Chronic Pain Scale (GCPS). The secondary outcome was the HRQoL which was measured using the Spanish version of EuroQoL Five Dimensions and Five Levels (EQ-5D-5L) as well as the PRS. Results. Significant differences (P0.05). Nevertheless, subjects referring CLBP showed greater levels in the PRS than patients with GTPS. Comparing both groups, the HRQoL showed statistical differences (P<0.05) in the “pain/discomfort” domain in the CLBP group with respect to the GTPS group, but not in the other domains. Conclusions. Patients who suffered from CLBP showed greater pain severity and HRQoL discomfort with regard to patients with GTPS. Despite greater scores for CLBP, the PRS did not seem to be different between both conditions.