Background: In fencing, lunge is the basis of most attacking motions and one of the first movements to be learned. However, it is not a consensus witch aspects of lower and upper body
kinematic and coordination are determinants for lunge performance, as even high-level fencers can use different strategies. We propose to identify body center of mass (BCM) and lower body kinematic
and joint coordination characteristics of good performance based on coach's criteria.
Methods: We performed a whole body kinematic analysis of a skilled epee's amateur fencing athlete (right-handed, 11 years old boy, two years fencing practitioner). Optitrack motion
capture system (Prime 13, 18 cameras, sampling rate 120Hz) was used to track the motion of retro-reflective markers fixed in the subject’s body and a stick placed in the epee’s tip. The subject
performed a lunge attack from a static en garde sixte position, after a warm-up period, in two conditions: a) without the presence of any target to hit b) in the presence of a static opponent (his
coach), having the chest as the target. The subject performed 4 trials/condition. The lower limbs joint angles and velocities in the sagittal plane (computed via Euler angles) and the body CM linear
displacement and velocity were calculated using the Visual3d software (5.01 version). The athlete’s coach (athlete and children's fencing teacher for 8 years) was invited to evaluate the recorded
performance (balance and posture during lunge) and to identify the best-performed trials, according to his own criteria. We compared the variables, extracted from the temporal series of the selected
physical quantities at different phases of the lunge, between the best-performed trials (B) and the others (O) and between the target conditions.
Results: Several aspects of lunge gesture differed between the two target conditions. However, irrespective of the static opponent presence, in B the lunge was performed with: higher
ankle dorsiflexion range in the armed side (AS), from lunge initiation (LI) until the beginning of the AS foot elevation (B: 5.4°±0.5°, O: 4.1°±0.3°, z-score: 2.1), and in the non-armed side (NAS)
prior to AS foot contact (B: 13°±3°,O: 4°±1°, z-score: 3.1); higher AS knee extension velocity prior to foot contact (B: 259°/s±17°/s, O: 197°/s± 4°/s, z-score: 3.5). In B, we observed less CM
vertical oscillation (CM upward displacement from the initial position - B: 0.8±0.2cm, O: 3.0±0.5cm, z-score: 3.0) and a lower CM final position (CM downward displacement form initial position – B:
13.4±0.5cm, O: 11.0±0.6 cm). In addition, lunge was performed with higher downward CM velocity before AS foot contact (B: 15±3cm/s, O: 6±2 cm/s, z-score: 2.9).
Conclusions: Proper ankle range of motion and knee extension velocity may be determinate for lunge stability, particularly, for a more stable and fast movement in the vertical
direction. We have already conducted a similar study focused on upper body kinematic that highlighted the importance of unarmed-arm gesture and posture to performance. Following analysis will consider
upper and lower body coordination and energy transfer between segments.