BackgroundLow back pain is one of the most prevalent musculoskeletal conditions in the world. Many exercise treatment options exist but few interventions have utilised free-weight resistance training. To investigate the effects of a free-weight-based resistance training intervention on pain and lumbar fat infiltration in those with chronic low back pain.MethodsThirty participants entered the study, 11 females (age=39.6±12.4 years, height=164 cm±5.3 cm, body mass=70.9±8.2 kg,) and 19 males (age=39.7±9.7 years, height=179±5.9 cm, body mass=86.6±15.9 kg). A 16-week, progressive, free-weight-based resistance training intervention was used. Participants completed three training sessions per week. Participants completed a Visual Analogue Pain Scale, Oswestry Disability Index and Euro-Qol V2 quality of life measure at baseline and every 4 weeks throughout the study. Three-dimensional kinematic and kinetic measures were used for biomechanical analysis of a bodyweight squat movement. Maximum strength was measured using an isometric mid-thigh pull, and lumbar paraspinal endurance was measured using a Biering-Sorensen test. Lumbar paraspinal fat infiltration was measured preintervention and postintervention using MRIs.ResultsPostintervention pain, disability and quality of life were all significantly improved. In addition, there was a significant reduction in fat infiltration at the L3L4 and L4L5 levels and increase in lumbar extension time to exhaustion of 18%.ConclusionsA free-weight-based resistance training intervention can be successfully utilised to improve pain, disability and quality of life in those with low back pain.

Welch, N, Richter, C, Franklyn-Miller, A, and Moran, K. Principal component analysis of the biomechanical factors associated with performance during cutting. J Strength Cond Res 35(6): 1715–1723, 2021—The main aim of the current study was to investigate the relationship between kinematic variables in cutting and performance outcome across different angled cuts through the use of principal component analysis and permutation testing. Twenty-five male intercounty Gaelic football players (23.5 ± 4.2 years, 183 ± 6 cm, and 83 ± 6.9 kg) participated in the study. Three-dimensional motion capture was used to perform a biomechanical analysis of 110 and 45° cutting tasks. Principal component analysis and permutation testing revealed one principal component within the 45° cut (r = 0.26) and 2 principal components within the 110° (r = 0.66 and 0.27) cut that consistently correlated with performance outcome. Within the 45° cut, the identified principal component was interpreted as relating to performance cues of maintaining a low center of mass during the concentric phase, using a shorter ground contact time, resisting a reduction in lateral center of mass to ankle and knee distance in the eccentric phase, and using faster and larger extensions of the hip and knee. Within the 110° cut, the first identified principal component was interpreted as relating to performance cues of maintaining a low center of mass during the concentric phase, using a shorter ground contact time, resisting a reduction in lateral center of mass to ankle and knee distance in the eccentric phase, and resisting hip flexion then using hip extension. The second principal component was interpreted as relating to a performance cue of leaning in the direction of the cut.

Welch, N, Richter, C, Moran, K, and Franklyn-Miller, A. Principal component analysis of the associations between kinetic variables in cutting and jumping, and cutting performance outcome.

No abstract