Hip Hinge Kinematics and Movement Confidence Before and After Founder Exercise Instruction in Healthy Adults: A...

Background: Impaired lumbopelvic control and inefficient bending mechanics are associated with low back pain and functional limitations. The Founder Exercise is a movement retraining strategy intended to promote hip-dominant movement, trunk control, and postural awareness during forward bending. However, empirical evidence examining movement performance following Founder Exercise instruction is limited. This study examined immediate pre-to-post differences in hip hinge kinematics and movement confidence surrounding a standardized Founder Exercise instructional session in healthy adults. Methods: A within-subject pretest-posttest design was used. Thirty-three healthy adults (72.7% female; mean age, 25.1 ± 2.9 years) completed assessments of foot orientation, sagittal-plane joint kinematics, and movement confidence before and after a single Founder Exercise instructional session. Joint kinematics were assessed using two-dimensional video analysis. Paired-samples t-tests or Wilcoxon signed-rank tests, as appropriate based on the distributions of the paired differences, were used to evaluate the kinematic outcomes. The exploratory summed confidence score and individual ordinal confidence items were evaluated using Wilcoxon signed-rank tests. Holm adjustments were applied separately to the 11 kinematic comparisons and the 10 individual-item comparisons. Results: Statistically significant immediate pre-to-post differences were observed in several kinematic variables. Hip flexion increased from 80.7° ± 18.1° at pretest to 104.6° ± 14.3° at posttest, shoulder flexion increased from 62.8° ± 23.9° to 145.3° ± 13.9°, and craniovertebral angle decreased from 25.7° ± 12.9° to 11.2° ± 10.0° (all p < 0.001). The summed score from the unvalidated, study-specific confidence scale was higher at posttest (median = 49.0, IQR = 40.0-50.0) than at pretest (median = 40.0, IQR = 36.0-50.0; p < 0.001). After Holm adjustment of the individual ordinal-item analyses, statistically significant differences remained for five of the 10 items; all confidence findings were considered exploratory. No statistically significant differences were observed in knee flexion or ankle motion after Holm adjustment. Conclusions: A brief Founder Exercise instructional session was followed by immediate differences in selected two-dimensional hip hinge angles and higher exploratory movement-confidence scores in healthy adults. These findings do not establish changes in lumbopelvic control, muscle activation, spinal loading, movement efficiency, or clinical outcomes. Controlled studies incorporating direct measures of lumbar and pelvic motion, muscle activity, external forces, and clinically relevant outcomes are needed before biomechanical or clinical conclusions can be drawn.