Inner Lines
The inner lines and arrows of the Enneagram symbol are primarily used with the Enneagram personality types in two ways: stress/security points and directions of integration/disintegration.
From Helen Palmer's books come the concepts of stress points and security points. The security points may also be referred to as non-stress or relaxation points. Each Enneagram type has a single stress point and a single security point. These points are found by following the inner lines. The stress point is found by following the line moving with the arrow (e.g., the stress point for type 6 would be type 3). The security point is found by following the line moving against the arrow (e.g., the security point for type 6 would be type 9). When under stress, a type may display characteristics of it's stress point (e.g., type 6 might present type 3 characteristics when the person is under stress). Likewise, when not stressed, a type may display characteristics of it's security point (e.g., type 6 might display type 9 characteristics when the person is not under stress).
From Don Riso's books come the concept of directions of integration and disintegration. The original concept pointed to paths of health (integration) and unhealth (disintegration). The line of integration (or health) was against the arrow and the line of disintegration (or unhealth) was with the arrow (e.g., type 6 would integrate by becoming more 9-like and disintegrate by becoming more 3-like).
Whether the connecting lines indicate stress points, disintegration, security points or integration, they are generally thought of as two additional influences on each personality type (e.g., a person identifying with type 6 would display both type 3 and type 9 characteristics).
