## 4 Discussion  
One of the main functions of ankle muscles is controlling the dorsi/plantarflexion of the foot during dynamic activities. The identification of ankle muscle pathologies is crucial to obtain an accurate diagnosis and in the prescription of orthotics. In most cases, in clinical practice, the forces exerted at the ankle are assessed by clinicians via joint manipulation. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Condition.** & **Direction of Force** & **Side** & **AFT [N]** & **AFT [\%BW]** \\ \hline \multirow{4}{*}{Fully extended knee} & \multirow{2}{*}{Dorsiflexion} & Dominant & 218 (145 296) * & 28.4 (113.35.9) * \\ \cline{3-5}  & & Non-Dominant & 205 (133 281) *,- & 27.8 (9.7.36.1) *,- \\ \cline{3-5}  & & Dominant & 201 (123 347) * & 29.5 (9.7 47.3) * \\ \cline{3-5}  & & Non-Dominant & 188 (106 318) *,- & 24.0 (54 38.6) *,- \\ \hline \multirow{4}{*}{Partially flexed knee} & \multirow{2}{*}{Dorsiflexion} & Dominant & 206 (128 289) *,- & 29.8 (11 37) *,- \\ \cline{3-5}  & & Non-Dominant & 195 (131 273) *,- & 27.8 (8.8 34.7) *,- \\ \cline{3-5}  & & Dominant & 178 (116 316) *,- & 27.5 (7.9 45.5) *,- \\ \cline{3-5}  & & Non-Dominant & 167 (114 285) *,- & 24.0 (7.5 36.1) *,- \\ \hline \hline \end{tabular}
\end{table} 
Table 1: AFT measurements in the healthy population. Median (10 th 90 th) of absolute AFT measurements [N] and normalized to body weight [%BW] across the 30 healthy participants with the extended knee and flexed knee in the dominant and non-dominant leg. Where * indicates statistically significant differences between dominant and non-dominant leg (\(p<0.001\)); * indicates statistically significant differences between dorsiflexion and plantarflexion in the same knee posture (\(p<0.001\)). Figure 3: Ankle force measurement in a foot-drop patient. Temporal profile of the maximum voluntary plantar- and dorsi-flexion force (N) in the affected (continuous line) and in the non-affected (dotted line) in one exemplary foot-drop patient with the knee extended. This study aimed to overcome the intrinsic limitations of such a subjective evaluation by preserving the same postural conditions normally used during physical examination. The setup proposed in this study showed significant intra-session repeatability in measuring ankle forces, with CVs of 5% and 8% for dorsiflexion and plantarflexion, respectively. This is comparable to the intra-session repeatability of the dorsiflexion measurements reported by [PERSON] at al. [6]. The average inter-session CVs can also be considered acceptable, albeit around 3-5% higher than the corresponding intra-session CVs under the same conditions. The slight decrease in measurement repeatability may be explained by variations in the relative positioning between foot and AFT across different sessions in addition to physiological variations in the subject's performance. Therefore, it should be highlighted that differences in ankle force up to 10% can be due to the variability highlighted above and not to the phenomenon under investigation. Indeed, variability in ankle forces up to 10% can be considered physiological, as reported also by [PERSON] et al. [9] for intra-session measurements. In addition, the intra-session repeatability observed here for dorsiflexion measurements is comparable to that reported by [PERSON] et al. [6] (CV = 4.2 \(\pm\) 3.6% and about 8% of all CVs exceeding 10%). While the proposed procedure can detect differences in ankle force greater than 16%, the appropriate repeatability of the apparatus should be assessed against the degree of accuracy needed for the specific application. Some limitations could be present when measuring ankle strength in patients with low muscle forces. In terms of absolute forces measured by the standard uniaxial load cell comprising the device, the ankle dorsiflexion forces recorded in this study were comparable to those acquired with a similar setup [2]. Likewise, [PERSON] et al.