Kinematics and kinetics of 2 styles of partial forward lunge.

OBJECTIVE: To evaluate the anterior shift of the body's center of gravity (CG) and the associated inertial forces produced by 2 styles of a partial forward lunge. SETTING: Gait-analysis laboratory of a research institution. PARTICIPANTS: 10 healthy volunteers. INTERVENTION: 3 trials of each lunge. MAIN OUTCOME MEASURES: Kinematic data were collected, and inertial reaction forces were resolved into net compressive and shear forces using an inverse dynamic model. RESULTS: Significantly (P < .001) greater anterior translation of the CG was found with an arms-in-front v arms-across-chest lunge style. No significant differences were found between the average peak inertial compressive and shear forces of the 2 styles (427 +/- 184 N v 426 +/- 187 N, -536 +/- 113 N v -538 +/- 127 N). CONCLUSION: Anterior translation of the CG was larger with the arms-forward partial-lunge position, creating increased balance demands. Both styles produced clinically safe (posteriorly directed) inertial shear forces, with greater anterior CG shift with the arms-forward style.

Coach talk: linguistic demands inherent in youth sports.

PURPOSE: This investigation expands the notion of academic language to extracurricular activities and provides preliminary data regarding linguistic expectations that are place on students who are participating in youth sports. METHOD: Five coaches of young girls' basketball teams (2 competitive; 3 recreational) were observed during practice sessions divided into individual versus group and stationary versus active contexts. Communication was characterized with various measures of content, form, and use. RESULTS: Coaches rarely used pauses or communicative repetitions. Recreational coaches' utterances contained more mazes than competitive coaches' utterances. Utterances used during stationary activities tended to be longer and contain more than one verb compared to utterances used during active activities; sentence fragments were more frequent during active contexts. All coaches used jargon quite frequently. CLINICAL IMPLICATIONS: The system reported here can be used to document linguistic demands in other extracurricular activities, such as music programs and scouting. Speech-language pathologists might include clinical activities to help students deal successfully with the linguistic requirements that are inherent in sporting activities.