This full paper concerns the use of gesture analysis to guide instructional approaches in engineering education. Engineering is rife with abstract mathematics and processes for quantifying physical phenomena. In engineering instruction, "formalisms first" is a practice that privileges formalisms over grounded and applied ways of knowing that are common in engineering curricula. By way of contrast, "progressive formalization" is an alternative pedagogical practice that intentionally grounds the meaning of mathematical formalisms in one's sensorimotor experiences in order that the formalisms are meaningful to learners. In the courses of explaining engineering concepts, instructors often make iconic gestures (gestures that represent objects, actions, and relationships) that are based in perception and action as a means for grounding domain knowledge prior to introducing formalisms. In response, students' gestures can be either concordant (i.e., conceptually aligned) or discordant (i.e., conceptually misaligned). The latter, also known as gesture-speech mismatches, are indices for states of transitional knowledge in which learners exhibit a readiness to learn. Thus, the current research observes the spontaneous gestures students make while describing torsional loading and investigates the added benefits of incorporating gesture into formative assessments of engineering education. Results indicate that students do use gestures as integral parts of their explanations in an engineering lab setting and that gestures and co-articulated speech were often matched. Instances of gesture-speech mismatches provides instructors opportunities to assess student knowledge, knowledge-in-transition, and initial learning and correct understandings prior to summative assessments.