This study aimed to determine if a quantifiable relationship exists between the peak sound amplitude and peak vertical ground reaction force (vGRF) and vertical loading rate during running. It also investigated whether differences in peak sound amplitude, contact time, lower limb kinematics, kinetics and foot strike technique existed when participants were verbally instructed to run quietly compared to their normal running. A total of 26 males completed running trials for two sound conditions: normal running and quiet running. Simple linear regressions revealed no significant relationships between impact sound and peak vGRF in the normal and quiet conditions and vertical loading rate in the normal condition. t-Tests revealed significant within-subject decreases in peak sound, peak vGRF and vertical loading rate during the quiet compared to the normal running condition. During the normal running condition, 15.4% of participants utilised a non-rearfoot strike technique compared to 76.9% in the quiet condition, which was corroborated by an increased ankle plantarflexion angle at initial contact. This study demonstrated that quieter impact sound is not directly associated with a lower peak vGRF or vertical loading rate. However, given the instructions to run quietly, participants effectively reduced peak impact sound, peak vGRF and vertical loading rate.

No abstract

Background Movement and posture are commonly believed to relate to non‐specific low back pain (NSLBP). While people with NSLBP appear to move and posture themselves differently from those without NSLBP, changes in movement and posture infrequently relate to improvements in NSLBP when analysed at a group‐level. Additionally, little is known about how movement or posture change when clinical outcome improves. Methods Within‐person relationships were investigated using a replicated, repeated measures, single‐case design in 12 people with persistent, disabling NSLBP. Individually relevant movement and posture were captured using wearable sensors on up to 20 occasions over a 22‐week period (5‐week baseline, 12‐week physiotherapy‐led intervention, 5‐week follow‐up), while pain and activity limitation were collected concomitantly. A series of cross‐correlation analyses estimated the presence, strength, and direction of relationships. Results Many participants (n = 10/12) had strong (e.g. r = 0.91, p = <0.001) relationships between changes in movement or posture and changes in pain and activity limitation, while some showed no strong association. Where relationships were observed, clinical improvement predominantly (93% or 57/61 relationships) related to increased spinal movement range and velocity during forward bending and lifting, reduced lumbar muscle EMG activity at maximum voluntary flexion, and increased posterior‐pelvic‐tilt during sitting and standing. Conclusion Within‐person changes to individually relevant movement and posture appear to often relate to clinical outcome, but not always. When changes were related, movement and posture appear to return towards being ‘less protective’, however causal directions remain unknown. Important activities, movements, and postural parameters varied across the participants, highlighting the potential importance of individualized management. Significance Changes to individually relevant movement and posture appear to often relate to clinical outcome, but not always. Patient‐specific activities, and movement or postural parameters that related to improved pain and activity limitation, varied across the 12 participants, highlighting the potential importance of individualised management. Where clinical improvements were related to changes in movement or posture, participants consistently returned towards being ‘less protective’ (increased range and speed of movement, increased posterior‐pelvic‐tilt during sitting and standing). Mechanisms and generalizability remain unclear.

As landing sound decreases, so does vGRF during a drop-landing task. These reductions were achieved by increasing ankle and knee joint excursions. Conversely, as the landing sound increases, so does vGRF. This was the result of decreasing ankle joint excursion and increasing hip joint excursion.

No abstract

Background Movement and posture are commonly believed to relate to low back pain (LBP). Yet, we know little about how people make sense of the relationship between their LBP, movement and posture, particularly after recovery. We aimed to qualitatively explore this understanding, how it changes and how it relates to quantitative changes. Methods A mixed method study in the context of an existing single‐case design involving 12 people with disabling non‐specific LBP. Interviews were conducted before and after a 12‐week physiotherapy‐led Cognitive Functional Therapy intervention, and qualitative findings from these were integrated with individualized, quantitative measures of movement, posture, psychological factors, pain and activity limitation. Results Strong beliefs about movement and posture were identified during the baseline interviews. Lived experiences of tension and stiffness characterized the embodiment of ‘nonconscious protection’, while healthcare and societal messages prompted pain‐related fear and ‘conscious protection’. Through varied journeys, most participants reported improvements over time with less protective movement and postural strategies. For some, being less protective required focused attention (‘conscious non‐protection’), but most returned to automatic, normal and fearless patterns (‘nonconscious non‐protection’), forgetting about their LBP. One participant reported no meaningful shift, remaining protective. Greater spinal range, faster movement, more relaxed postures and less back muscle EMG accompanied positive changes in self‐report factors. Conclusion The findings offer a framework for understanding how people make sense of movement and posture during the process of recovery from persistent, disabling non‐specific LBP. This involved a re‐conceptualisation of movement and posture, from threatening, to therapeutic. Significance Findings from qualitative interviews before and after a Cognitive Functional Therapy intervention in 12 people with disabling low back pain highlighted an individualized recovery journey from conscious and nonconscious protection to conscious non‐protection for some, and nonconscious non‐protection for many. Pre and post‐quantitative measures of movement, posture, psychological factors, pain and activity limitation integrated well with the qualitative findings. The findings suggest movement and posture may form part of a multidimensional pain schema.

No abstract