The principal objective of our research is to characterize key exercises that represent significant milestones in the rehabilitation process, employing biomechanical parameters to facilitate the distinction between stages of progression.
We conducted an observational cross-sectional study on healthy volunteers (30 years), approved by an ethics committee. Subjects with a history of lower extremity disease were excluded. Movement data was collected, including the following hierarchy of exercise progressions: sit-to-stand-supported (STSS) - sit-to-stand (STS) - squat, stair climbing supported (SCS) - stair climbing (SC) - step-up, single-leg-stance-supported (SLSS) - single-leg-stance (SLS) - single-leg-stance-advanced (SLSA). Motion data was captured using a marker-less system (CapturyLive, v255, TheCaptury, Germany) and used for musculoskeletal simulations in the AnyBody Modeling System (v7.4.4, AnyBodyTechnology, Denmark) with a full-body model. ANOVA or Welch-Test with Bonferroni Post-Hoc was used to describe the anterior-posterior joint reaction force (JRF) normalized for body weight (BW) for each exercise. Positive values indicate an anterior JRF, and negative values a posterior JRF.
We recruited 31 subjects (female: 23/74.2%) with a mean age of 22.81 years (SD:2.18). The analysis showed a significant difference in minimum JRF for STSS, STS, and squat (Welch-Test: F(2,56.421)=71.216, p0.001). Post-hoc analysis revealed that posterior JRF for STSS (mean:-2.63BW, SD:0.53) was lower than for STS (mean:-3.74BW, SD:0.42, p0.001), and STS was lower than squat (mean:-4.02BW, SD:0.35, p=0.043). No significant differences were observed in maximum JRF in the posterior direction (ANOVA: F(2,87)=1.151, p=0.324). For single-leg-stance exercises, the minimum JRF was similar for SLSS (mean:-0.34BW, SD:0.22) and SLS (mean:-0.55BW, SD:0.25, p=0.056), but higher in the posterior direction for SLSA (mean:-0.98BW, SD:0.49, p0.001; Welch-Test: F(2,54.379)=22.536, p0.001). Maximum JRF differences were also significant (ANOVA: F(2,87)=11.546, p0.001), with SLSS (mean:0.01BW, SD:0.22) showing a significant higher anterior JRF compared to SLS (mean:-0.16BW, SD:0.19, p=0.020). In the progression from SCS, SC to step-up, there was a significant difference in minimum JRF (ANOVA: F(2,87)=5.33, p=0.007), but not in maximum JRF (ANOVA: F(2,87)=0.624, p=0.538). SCS (mean:-3.42BW, SD:0.38) and SC (mean:-3.48BW, SD:0.54) showed no difference (p=1.000), but SC was significantly higher than step-up (mean:-3.58BW, SD:0.62, p=0.036).
The exercises show differences in the JRF according to stages of progression, which can be taken into account when selecting exercises. Future research should address the group of patients who have undergone knee arthroplasty.
In the future, it may be feasible to quantify patients' resilience based on sensor data and associate this with the optimal progression of an exercise sequence throughout the rehabilitation process.
rehabilitation
biomechanic
